My baby doesn't like my in-laws! Any tips on how I can get her to warm up to them?

Babies can "smell" that mummy is close by thats when they will start fussing when other people is carrying them. Baby will be much clingy if she is breastfed. You can leave baby awhile in your in-laws' care while you go to nearby supermarket for a small walk so that baby can get used to them. It will take a step at a time so do not rush into it if not baby will totally reject other people.