LO always cries at parent's house

LO is currently 3.5 months. She has been crying when we're atmy parent's & in law's eversince 2MO. We keep alternating each week to both houses.. My mum actually have been with me since day 1 until my confinement ends. She has also taken care of LO for a week by herself when i fell sick. I'm guessing that it's normal but is there any way to make her feel better & more comfortable? :/