I was recently a birth partner for one of my best friends. Was with her and her husband for all 36 hours of her labour except the last 20 mins, as she was taken through to theatre.
The hospital was the most uncomfortable and uncompassionate place to be for that period of time, nowhere to rest, hard plastic seats, rubbish food, busy stressed staff that have more on their minds than caring if the labouring women's friends and family are ok. I've given birth, but can honestly say that I found being there for my friend incredibly stressful emotional and scarey, as difficult in a different way.
Her parents turned up at the hospital at the start of the second day and just had to sit in the rubbish canteen all day. They weren't allowed up to the ward, weren't any help, were just a bit annoying as we felt we needed to keep them updated.
When she got taken to theatre it was 6pm. The baby was born at 620pm, but I was left in the delivery room till 730 worrying and crying wondering what was happening. I went through and asked the reception of the labour ward then what was happening, abd was told that she'd had her baby, but they couldn't give any more details, and visiting hours were over in half an hour so I may aswell just go home. I explained that her parents were down stairs waiting for news, and they said I should just tell them to go home too.
Was unbelievable how dogmatic and protocol driven a hospital can be. I was with my friend for 36 hours, but because visiting hours were over I had to just leave. I packed up her stuff in tears, and was on my way down to tell her parents when a nice nurse told me "off the record" what ward they were on. I got her parents and we made it to the ward with 10 mins of visiting to spare, only to have the ward staff deny my friend was there atall. It was only the fact that her husband saw us at the ward door and came and got us that we saw her at all. And she and her husband had been desperate to see us, but their phones were stillin the delivery room.
Your MIL may not be top priority . It may not be the fairy tale she thinks it'll be. Even having giving birth recently, I was totally unprepAred for how difficult being there was. She's in for a shock if she does turn up