Honestly, first you should ask yourselves:
- Is this really necessary?
- If so: Why is it?
- What will change because of a female mannequin?
- What is to be gained?
Honestly, I think this is the less useful topic in the history of ever: You already have free assets with female characters, you have pack (which uses the SAME animation pack for each character) use them for prototying if you want to. There’s no need for Epic to include one, animators aren’t cheap, modelers either, and this won’t be make a change in the engine quality.