Baby cries only with MIL

My baby is 4.5 months now and since day 1 everytime my MIL tries to hold her she cries (or even sometimes when she comes close and talks to her). We try to let her warm up to her but it takes a long time (longer than we have to with anyone else).

She sees my MIL the most out of everyone but has the hardest time with her.

Has anyone else's baby done this?