A long one, sorry. Just a bit of an AIBU / checking if my gut instinct is right about this situation or not.
A bit of context so as not to drip feed - My MIL has 8 DC and absolutely loves babies, and says she would have had more if nature had let her. My DH (the eldest) does love his mum but has always found her a bit stifling / controlling of him. As he got older he felt she tried to keep him from growing up, for example not wanting him to go off to university (which he did anyway) and stifling him a bit, eg calling him early mornings every day during his finals to check he was up, even after he asked her to stop. After university he moved to a city 3 hrs away from his mum's home for his job, and as an adult he has generally seen her about 3-4 times a year. They are not really close but they get on to a polite level, if that makes sense. She has always been fine to me, although she was quite overly invested in our wedding and there were a few tears when we didn't do things as traditionally as she would have chosen, but mainly directed at DH rather than me. She was also quite full on during my pregnancy, albeit via text as we were in lockdown, eg asking us to text her as soon as I went into labour (which we didn't do). I know she was incredibly keen to be a granny so I did understand she was very excited.
When our DD was born it was during lockdown as well so MIL didn't see as much of the baby as we would have normally expected, (for the first month it wasn't even legal) but we arranged some outdoor gatherings in the warmer weather and picnics etc. From the first day MIL was very clear that she wanted to look after DD on her own. At our first meeting she offered to drive 3 hrs to look after DD 3 days a week so I could go back to work. (This would be a 6 hr round trip per day). I was polite but non-committal as it felt too soon to be thinking about this with DD only tiny and it had come out of the blue. Afterwards DH said to me that he didn't feel comfortable with DMIL looking after our DD. He said that her reasons for offering were for her own needs rather than thinking first about DD or us. I did feel it was quite a "full on" offer from MIL considering she's not really close to DH, and the 6 hour round trip making it completely impractical! In my gut I did feel she wanted to get back that feeling of having a baby to look after.
Anyway, a year later after a number of other meet ups, we asked MIL and DH's sister to visit for the day, and we suggested that MIL might like to spend some time with DD. (She had been texting us to ask about this on a fortnightly basis, always framing it as "to help you out" but my DH still felt a bit uneasy). Anyway we felt that due to lockdown our DD hadn't had any opportunity to spend time away from us so it would be good for her and it would be nice for MIL, as we did feel sorry for her not having seen as much of us all due to Covid. So we arranged to go out for lunch just me and DH whilst MIL and SIL stayed in our home with DD. This was very much something we felt we were doing for MIL.
Bearing in mind this was the first time we had ever left DD, and in my case (due to lockdown) the first time I had ever been apart from her at all except from when DH looked after her. As you can imagine I was slightly nervous. Not being all "PFB" I hope, just in the normal natural sense that as a first time mum I was leaving my baby to be cared for someone other than my husband and I felt a bit anxious, which I think is understandable. But I knew it was a good thing to be doing and that she'd be perfectly safe.
I felt sure that in spite of MIL's obvious desire to have DD all to herself, as a mum of 8 she would definitely sympathise with the nerves I felt and be considerate about it. I showed her round DD's room, not teaching her to suck eggs as I knew she's experienced looking after babies, but just pointing out stuff she'd need to know like where nappies and wipes were kept, what to give as a snack etc. As I did this she changed a bit, and became impatient and seemed to be rushing me along a bit, saying "yes yes" as if she was itching for us to leave.
Just before DH and I left the house, I said to MIL "look I know I'm being silly, and everything will be absolutely fine, but I'd really appreciate it if you could text us after an hour or so, just to let us know DD is okay, as it's the first time we've left her". MIL said of course.
At the cafe where we were waiting, after an hour there was no text. We both felt nervous but knew we were just experiencing what every first time parents do, and decided to try and enjoy our lunch and not worry. After 1.5 hours however, we became a little bit anxious. DH said he would send a casual text to MIL just to check in. He did so but there was no reply. She always texts back straight away so that made us more nervy! Then I said, look I know it's silly but can we just give her a quick call and say we just wanted to check in. So DH rang her but there was no answer. That only made us feel more nervous! So then we decided to call SIL and she didn't answer! By now I felt slightly nervous, even though I knew it was most likely to be fine, but I felt a bit annoyed as I had explicitly asked MIL to text us.
Anyway, long story short SIL finally rang us another hour later saying all was fine but they had not seen their phones.
We returned home after about 3 hrs. When we got home the first thing MIL said was it all went brilliantly and that "DD didn't miss her mummy and daddy one bit". I felt this was a slightly ill-judged remark, but at the time I was feeling a bit sensitive because of the situation.
MIL continued to say how smoothly it had all gone and how she'd be happy to do this every week or more if we wanted it. She left the room to go to the bathroom and during normal conversation SIL let it slip that DD had been in tears - apparently she had seen a photo of me on the wall and had cried for mama and needed comforting. Nothing major and after 20 minutes she'd been fine, but why didn't MIL just tell us this outright?
After the visit, DH said that he felt his mum was painting it all out to be smooth and perfect so that we would ask her to look after DD more often. He said he felt she was being a bit disingenuous. I felt a lack of trust in MIL after her failing to phone us. I felt like this was a basic boundary that she had overstepped.
We are now at the stage where DD is older and so far we haven't left her with MIL again. We only tend to see DH's family a handful of times a year anyway, but MIL has been asking and asking to look after DD, and suggesting set days etc. She even bought an expensive Wendy house which her partner built in her garden, even though we haven't been to her house with DD before!
My gut feeling is that I don't trust her to look after DD alone. Not because I don't think DD would be safe - I'm quite sure she would be physically safe with MIL, but AIBU to feel that MIL's boundaries feel a bit off? Eg I can imagine a situation where DD was crying, sick or slightly bumped her head or something, where an objective carer or nanny would think "right, I'd better call mum" but where MIL might think she will deal with it herself, cover it all up and then not tell me about it later.