To the spoiled comment. I try to pretend it is a compliment and say yep they're only little for so long.
To the Mom situation.. I had this problem horribley with my MIL. We lived 15 minutes away but my DS screamed the entire car ride, so when we got out he wanted mommy of course to nurse him to calm him down. MIL would seriously meet us at the car door. She would take him out and walk away. It only stopped when my husband said Mom you need to give hima minute, he will warm up to you alot faster if you give him time. Trust me he holds grudges. (said with a smile to ease things over) And refused to hand him over. Now I am stronger with my DD and I do not hand her over till she is ready and I say nicely she just woke up and needs a minute. And when MIL leans in to take her I do not hand her over. Now she waits till the LOs come to her and now they actually like her instead of being afraid she was going to take them the wole tiem we were there.