My parents, my brother and SIL and my husband's brother all either ask us what they can get the kids for Christmas/birthday or if they have an idea themselves they'll message us to ask if it's ok.
My in laws just buy whatever they want for the kids. For the most part this is fine, the presents they buy are always lovely, but it has caused a few problems. For our son's first Christmas they bought the gift we were planning to get him. Thankfully they did tell us they'd bought it before we did, but it then meant we had to rethink what we were getting quite late on.
After that we (well my husband) asked them to check with us before buying any gifts, mainly to avoid duplicates. They've sort of managed to do this, although they do occasionally buy something and then just tell us, and think this is the same as telling us in advance. For Christmas this year we said we could give them some ideas if they were stuck for things to get, and they said yes so we gave them some ideas and they picked some. All great.
Our son's birthday is in January and I said to my husband we might need to ask if they want some birthday present ideas soon (they like to sort everything really far ahead of time). When he was on the phone to them yesterday they mentioned they would send the kids' Christmas and son's birthday present down when BIL visits next week. This was a surprise to him as they hadn't mentioned a birthday present, so he messaged to ask what is. Turns out they've bought a smart watch for our 3 year old. We are trying to keep him from screens as much as possible for as long as possible, so my husband has asked if they'd return it (said it's a bit old for him) and gave them a few ideas for something more suitable.
FIL is now apparently upset and said he doesn't want to return it, and he doesn't mind if son doesn't like it as they'll also be giving him cash. I don't think he understands/accepts that we don't want him to have it, it's not that he won't like it (I'm sure he'd love it, that's part of the problem!)
Sorry just realised this is really long, but basically just wondered if it's normal for extended family to run presents past you before buying for your young kids?