I, too, think that some people are taking their dislike of Mac's Mom way too far. She's not heartless!
It'd be nice if Frankie confronted her, but I really doubt she would "angrily yell" and "chew her out" like some people her said. I think Frankie would instead have a civilized chat with her, in which she would try to get Mac's Mom to understand her and the Foster's stance on IFs... and maybe--just
maybe--convince her to allow Bloo to stay at the apartment with Mac once in a while.