A and B have worked together for 25+ years. Originally in a very intense 1:1 environment- think NHS. Now less so but still in the same environment. B is married to C.
B and C are godparents to A's DD. A had her DD while single. A didn't realise she was pregnant until very late and had no real plans for raising DD as a single parent. B promised to support her.
A's DD is now 8. B and C have gone above and beyond to help out with childcare since she was born, which can be very difficult because A and B's job involves shifts and unpredictable hours. C doesn't work, so most of this is done by her. B and C's older DC also often babysit, do the school run etc, and are paid by A to do this. A's DD is treated like part of B and C's family when with them. A has always been willing to step in with B and C's DC whenever needed over the years, but this has been much less as C has always been home with the DC.
B is very involved with A's DD- will go to all her sports fixtures, school plays, recitals etc. B and C's DC have started to resent this, because B often missed out on these when they were growing up. This was usually due to work at the time, but B now doesn't make the same effort to get to things for younger DC and DGC that he does for A's DD. C is no longer happy with the arrangement, feels that B is too involved with A's DD and they are having her too often.
A's DD has a sports fixture coming up and needs to be accompanied by a parent/other responsible adult. The fixture is a long drive away and will take up the whole weekend. B has volunteered to take A's DD, as she will be working that weekend. C isn't happy as she wasn't asked first. The sports fixture will likely be one of many next year.
C feels that B is putting helping out A and her DD above his own family, and wants A to sort her own childcare from now on. A and B feel that B and the older DC have been volunteering (and the older DC are being paid) and as long as B is happy to be involved, the arrangement should continue.
Who is being unreasonable?