I think it was more of a "I'm sorry I can't put you first over my children (ever)" instead of actually feeling bad for choosing her children over him here. So I don't feel like it really says anything about her qualities as a mother.
I think it's a normal thing to say though... like she's apologizing in case her lover felt "neglected" since she knows she will always prioritize her children. Like the comment before me said, she won't "ever" put Daniel first in any situation if all of them are in one dangerous situation. If I were her children I wouldn't think negatively of her either, like it's a normal and understandable thing to say to your lover.when you are a mother with kids and its NOT your partner's kids.
Just like how Daniel would say "whose bastard would feel neglected when their lovers prioritize her child" (roughly) for them it was like "what kind of brat we are if we would feel betrayed when our mom said that she felt sorry to his lovers for prioritizing us" cuz they know they are "prioritized" over her lover. I would feel extremely loved by her instead.
I know the author probably added that last part to show how good Daniel is, but cmon which decent mother goes 'im sorry for putting my children first'
Especially after everything we've seen from her, that felt so out of character