I don't really think MIL was rude (she obviously didn't know that there was an urgent need to start right at 7:00). In her mind, she had three hours before she needed to leave.
A simple knock on the door would have prevented all. "Hey, MIL, we're ready to start unwrapping now!"
Urgent? is a bit of an overstatement, but MIL knew there was only a short window to accomplish the purpose of the MIL's trip: to attend the opening of gifts with the new grandbaby. To refresh:
From the OP:
Before going to bed Christmas Eve, we discussed the next morning--we told them that DD usually gets up around 7am, and so we would open presents then. We told them that DD has a very short window when she wakes up in the morning before she's ready for a power nap (an hour if we're lucky, including her bottle). DD's room is right next to the guest room and they assured us they'd hear her get up and we'd do presents then.
Oh yes, I understood that but MIL apparently didn't see the urgency despite being told that there was a need for it. Or maybe she thought that the gifts could be opened after the nap which was described as being an hour. Knocking on the door would have eliminated the OP's anxiety and allowed the morning to proceed. I see the coffee pot reply as a bit of a red herring.
Except in the OP's update, MIL is specifically told that there will be a short window until the nap, MIL is planning on leaving before the nap is over, and MIL is the one insisting on being present to watch the gift-opening. So she's created the urgency and still proceeds on her own invented schedule after agreeing to something else. Sounds controlling to me.
This sums up pretty well how I felt about it.
As far as the nap length/timing--DD is three months old and her nap schedule is still pretty erratic, and in fact most of the time still naps in-arms. So, about the only thing we could count on was having about an hour of happiness until she melted down, and then doing the best we can from there. It's not a matter of her napping for a known amount of time and being ready to go again, or just being able to put her in her crib and carry on with Christmas morning with just the adults.
I was bothered by it because it did seem subtly controlling to me. This year, we announced that while we would keep alternating Thanksgiving between families, we were starting our new tradition of being in our own home for Christmas, and whoever wanted to join us was welcome. The tone of it was very much 'Join us as we celebrate in our chosen way.' Our chosen way was to open presents with the baby first thing in the morning. She indicated she wanted to participate in that, and I'm sure she would have been very hurt if we had opened without her. We even asked her specifically the night before if she wanted us to wake her or knock, which prompted the comment of 'No, we'll hear you get up.' DH did eventually go up and get her. He is normally very, very laid back about things and doesn't easily take offense, and still he was frustrated that we're obviously awake and up, we can hear his mother talking, and yet she hadn't made her grand appearance.
