Baby awake for hours after seeing Grandmother

This is going to sound crazy. The last 6 times my 10 month old has seen my mother in law, the baby is wide awake and ready to play for 4 hours straight in the night (Usually 11-3 am).

She has only ever done this after seeing her. The rest of the time she sleeps 12 hours with an occasional wake up to nurse. We are always there so know my MIL isn’t doing anything wrong. She is extremely high energy though. Loud and very anxious the baby will fall or get hurt. Freaking out if she does anything “dangerous” like pull herself up to stand holding on the coffee table, puts a toy in her mouth, crawls over to her dog, and basically anything else that isn’t sitting still.

We have even seen her for 5 minutes and she just talks to the baby through the car window. It still makes her be awake for hours in the night.

Has anyone experienced this before? It’s hard to believe but I think it’s too much of a coincidence. Any advice? If we had something to try I would talk to her about it but I don’t want to hurt her feelings.