Wife and daughter ILR submitted same time-diff wait times

[wunit5times]

i applied for wife and son, plus daughter (just turned 18 at the time therefore separately. she was in process of a-levels still)

applied in mid Jan, sending both applications together. both were aknowledged and everyone enrolled their biometrics together.

the wife and son (under 18) application was granted around 2 months ago, but still no answer for the daughter.

is this normal? perhaps because daughter application depends on wife passing?

also, what happens when she finishes her a-levels (now taking exams so officially finish in June i think)? does this affect the result if no answer has been given by this point?

thanks in advance