I just got my extension based on marriage on Tuesday. The rule is two months before application than you get a consideration stamp for a month but you can use the money after the application is approved.
I am on a marriage extension and have two registered permanent addresses where I divide my time. I have only had one visit which was the original first visit the address down south has never been looked at. They assess each application so there must be a question mark on yours to make them do this. My wife does all my paperwork and deals directly with immigration so get your wife to ask what's wrong she knows how to deal with authority without getting them angry.
Ok your sort of goosed than. The ex is obviously getting good advice from some where. But the embassy has to give her a passport if she is a citizen but the mother won't sign the release to travel. If the communication lines are cut with the motor you probably have to wait till she is eighteen sad I know. Just an excuse to get out of damp Ireland for a holiday in Thailand.
Not qualified to give advice here. But I have already had 3 extensions based on marriage they look for 400k in bank account 2 months prior to day of application. The home visit is always for a first application but I am sure they can do it anytime it's really up to them.