But the mother is happily in a new relationship with a baby on the way, so definitely not 'upset'
🙄
Your posts are laced in judgment of the mother, OP.
I do not agree that those exact words are reasonable or fair to say to a 5 yo, of course not.
However, one statement cannot be taken as a true indication of how this mother parents, or as PPs have said, whether the mum said this or in fact the child had picked it up indirectly or overheard, for example.
I do not agree with lying to children - my own DC have sadly had to deal with a highly emotionally abusive father. No, I wouldn't say this exactly, but I've been honest about his lack of capacity as a parent, that this doesn't reflect on them & they need to trust their own judgment & believe in themselves 💯 (I also did everything I could to support any element of their relationship, regardless of my feelings towards their father.).
The idea that a parent shoud directly lie as suggested by a PP ('That she's the apple of her dads eye, but he can't see her at the moment because he's working away.') I think is really wrong. I can honestly say I've never lied to them in these matters, but of course that doesn't mean telling them everything at an age when they are too young either.