No, chateaurouge, the problem is that a lot of mothers (please note, I have NOT said all mothers) think they have "more" rights to children post separation/divorce.
this is a child with a ver hands on father. currently, there is a potential run of 7 days where she does not see him (from one mid week to the next, if the weekend is with her mother).
but that is ok, because it is not the mother missing out.
never mind that she probably misses her father in this week, or that her father misses her.
that's ok, because he is the father, and therefore has less right to see his daughter.
the OP presumably has no worries about her dd's safety and care when she goes to stay with her father. the OP also did not mention that her dd has any problems settling with her father, or any worries for the 2 nights she is there.
so why shouldn't this become 3 nights, or 4, or 5? why shouldn't it build up to a week?
the only reason given - that it "mightbe too long" is vague to the point of ridiculous.
what isn't too long then? 7 nights? 6? 5? who has set this arbitrary boundary?
yes, I do understand how hard it must be to be away form your children for any length of time, but can't you see this is exactly what this girl's father feels every other week? not once a year, or once every blue moon when the mother agrees.
it shoud not be this way - and if the OP truly wants to put her dd first, she will do everyhting she can to help her have a solid functioning relationship with her father - which will include longer stays.