Could it be that she felt you could be tired after a long day of work and want to help care for baby when baby is fussy? it's only the first day, perhaps tomorrow when you see baby you can say 'mummy misses you when at work/ I have waited the whole day to carry you' to baby in the presence of your mil and husband. repeat afew times to get your message across.. if your mil wants to help you can also tell her you want to spend more time bonding with baby and she must be tired after whole day caring for baby. if she still insist or take baby away then perhaps disxuss with your husband and see what can be done..