Hi, OP here.
Thanks so much everyone. So many responses and so much to think about. I can't address everyone individually but I do send general thanks and true appreciation.
A bit of background that I really don't think is pertinent but may be interesting to you.
We are not a family group but a long term friendship group. It formed in the city we are all from in high school and university. They've been friends for between 15-25 years depending on the individuals. Mostly they are between 32-35 years old. I'm a bit older at 38 and am a late comer to the group having been with BF for only 5 years. John moved up to the farm to be with Gina about 2 years ago. It's about 8 hours drive away from the city where the rest of us live. John is best friends with Barry and has been for 25 years. Some have children (mostly very young) and some are just starting to and some (like BF) probably won't have children. I'm the odd one out with a teenager.
John is lonely up at the farm and has been begging the rest of us to come up to visit. That the visit of so many happened at the same time was not organised. It was a coincidence. There were two long weekends after each other and we all ended up deciding to go up there separately. No real invites just a general invitation. Jane was welcome and expected. But nothing had been organised. Until we got there we had expected to go off on our own most days and then get back together in the nights. Barry and Sue changed that and we went along with their plans mostly.
One day BF and I did get up early and go to do our own thing as there was a walk I wanted to do that was not child friendly. Sue was quite upset about that but I did insist as I needed time out.
I had no problem with Jane at the wineries, breweries and bars, they were adult activities but not adult places. Not rough loud or places that children weren't welcome. One winery had an enormous hedge maze.
I noticed a suggestion that maybe the friends were disrupting Jane from quiet play on her own. She had a small bucket of toys but wasn't really playing with them on her own. When she did we left her alone. She would pull at her parents legs and arms until they'd pick her up and hug her, they'd then turn her around, put her down and send her on her way. She would then walk around the house crying or just making noise, or pulling stuff out and throwing it. If we suggested that they should play with her or watch her, they'd start fighting over who's turn it was or send her over to the other one. We should have said something. I know we should have. But I felt so sorry for her, and the noise was giving me a headache so I just started playing with her and so did everyone else and it sort of snowballed from there.
The house was not at all child proof and I am not exaggerating. She had to be watched at all times in the living areas. That was John's decree. There were also two dogs that were not acclimatised to children and one did get a little snappy at Jane. I had medicines in my room as did one of the other women. There were household chemicals in low cupboards and knives on benches. Down the corridor, through a door, was the garage which had the farm chemicals and so on until John rebuilds the outdoor shed. Not a safe unsupervised environment. Jane could open the doors, I saw her do it to get into the music room to play the piano. She could just reach up and turn the door knobs. I also saw her climb out of the porta-cot.
Barry and Sue have had a hard time lately and I don't think they are coping well. I think they saw the holiday as a time to relax and took it a little too far. Normally they are a bit better but still lazy. They keep Jane fed, clothed and clean. As to why we are friends with them, Barry would give you the shirt off his back if he thought you needed it and probably even if you didn't. He's smart, fun and generally a nice guy. Sue is a little difficult at times but she is also a good person and comes as a package deal with Barry.
I'm not angry with them today. I'm over it. I'll watch them and make sure I'm a good friend/surrogate aunt to Jane. BF and I discussed it this morning and we are going to offer Barry and Sue more support with Jane and more time out to help them cope better, so Jane knows she is treasured and loved and Barry and Sue don't break under the stress.