Already we can see that Perdita is quite a strong leader. A Df and Wp of 7 means that she is at an advantage to all but the strongest attackers and casters and 10 Wd mean that she can take a bit of a beating. The trade-off is that she only has a cache of 2SS, meaning that you may want to consider forgoing some upgrades in order to ensure you have enough SS to spend during the game.
AbilitiesPerdita, like most Family members, has the COMPANION ability. This allows you to 'chain' activations for this model, if another model finishes its activation within 6". When I first started playing this was the first ability I used almost every time, getting more shots off against a model seems like a really big deal but the more I played the more I started to realise that it was quite situational. Rather than try and activate all my models as soon as possible I learned that in Malifaux you need to be able to react to your opponent and if all your models have already activated then there is no response that can be made.
Companion should be used primarily when you either have to get to a particular scheme or objective in time or when it's absolutely necessary to kill an opponents model before they can attack back. Always try and not use it when you can but play to ensure that the option is there and another model can be activated if it is needed.
RELOCATE allows Perdita to discard a card at the beginning of her activation and push up to 8" towards a friendly family model. This allows Perdita to lead from the rear (along with a 14" range) in a lot of cases and helps define how The Latigo Posse can be played. Being able to move 8" towards a model that is in trouble and still be able to get all 3 shots off can be the difference between losing a model or even losing the game. This does mean though that she is better to activate later on in the turn when you may be less likely to need your control cards as doing so first simply reduces options for the rest of the turn.
Perdita also has a defensive trigger QUICK DRAW, where if a Sh action fails against a Mask triggered Df, Perdita returns fire, flipping for 2/3/4 wounds with a negative flip. Her high Df of 7 does mean that anybody shooting at her needs to be aware that it could all go horribly wrong for them and keeping Masks in hand is particularly useful.
Her final ability is POINT BLANK, this gives her a Ram trigger to all Sh actions while engaged. This may seem pointless (as you can't shoot while engaged) however Perdita is unique in that her main attack (a Sh action) can also be used while engaged.
Attack ActionsPerdita's main attack, PEACEBRINGER, is a Sh 7 against Df with Range 14" but also can be used within 2" if engaged. It's spread of 2/4/5 damage is good, though not amazing but Ram triggers do +1 damage and Masks gain a positive damage flip. Perdita can very easily take down a target in a single round of activations.
Beyond just shooting Perdita also has a Ca action, OBEY. For Ca 7, TN 14 Masks, against Wp Perdita can force another (non-leader) model to take an action. So now that model that you activated first and your opponent thought he could ignore can attack again or move out of the way or drop that scheme marker. Even better is forcing an opponents heavy hitter to target someone they thought was completely out of range/sight or to run away or even pick up that scheme marker they just dropped #lols.
Tactical ActionsShe has 1 zero action, HERO'S GAMBLE, that discards the control hand and draws an equal amout of cards. This is another great reason to keep Perdita's activation as late in to the turn as possible. A control hand of 1, 2, 3, 12, 12, 13 looks a lot better to discard after you are down to just 1, 2, and 3. It's Perdita's only zero action without upgrades and so can always be used and means you can maintain pressure right up until the end of the turn.
FINGER ON THE TRIGGER is a defensive action that lasts until the next activation. It activates the condition "Faster 'n You" and will allow Perdita to shoot an enemy model within 12" if that model performs a Sh or Cg action. This ability would more likely be used with defensive schemes to slow an enemy advance and if you are playing a defensive scheme activating this and GUILD RIFLEMAN's STAND AND FIRE means that nobody is likely to charge allowing you get more shots off.
UpgradesPerdita has 3 exclusive upgrades that have a place, however the best one is probably TRICK SHOOTING for 2SS. Several crews will rely on sneaking up on you without getting shot or being INCORPOREAL or having enough ARMOR to deal with it. Trick Shooting counters both of those with 2 separate zero actions. BULLET BENDING lets Perdita ignore cover. No more negative flips for hard cover, just back to dealing straight up shots and damage. The other action is TRUE MARK this lets Perdita ignore Incorporeal and Armor, dealing full damage to Incorporeal units in particular is nasty as they usually have less hit points to make up for that ability. If you don't know what your opponent is going to bring to the field then Trick Shooting is my default upgrade.
AURA ANCESTRAL 1SS is a good upgrade to take against casting crews as they tend to want to do things to your crew and it gives 2 helpful passive abilities. SEE THE UNSEEN allows Perdita to ignore any targeting duels, such as a Horror duel but ORTEGA PRESENCE extends an 8" aura giving Family models in LoS +2 Wp. When playing this upgrade you'll likely want to have Perdita closer to the action in order for more models to gain the bonus. Make sure she is where the enemy caster(s) are and not on the opposing flank.
OS VEO 2SS is also a good upgrade against other shooty crews (Gremlins say) and casters with abilities that can take out your Leader. STUBBORN is a passive ability that forces your opponent to take a negative flip to any attack resisted by Perdita's Wp. BULLET PROOF reduces Sh damage by 2, to a minimum of 1. More useful if leading from the front and combos quite well with Aura Ancestral against Arcanists in particular.
SummaryLead from the rear - long range and potential for quick movement should action be required
Keep high Masks in control hand - With defensive, casting and shooting actions all requiring Masks holding a handful of Masks provides the most options for Perdita
Activate late - Can use up high value control cards and swap the remaining as well as 'reactivate' models with Obey, if defensive can also gives the whole turn on overwatch
There are of course times when you will need Perdita to do something else dependent upon Schemes and other models available but I will cover them as the models and situations come up.