I just wanted to put in some input on this, unfortunately it is not "I support the idea" input but I think it's good solid input on the topic in question that should be considered.
I understand the OP's intentions are marvelous

But, I firmly believe it is counter-productive to keep dividing up an under-active forum, the subforums will always go ignored and people won't get the advice/answers they are looking for.
Creating futher divisions in an under-active forum actually serves to
keep a forum under-active. Topics in sub-forums go unnoticed by people casually dropping by to see any "updates", the average person does not automatically check subforums, and if someone sees no activity in a main forum they are more likely to simply duck in and duck out, than stick around to participate.
I think this one should be placed on the back burner maybe, until a future time when perhaps we have more activity here. That being said, after 5 years on CF, CC has always been one of the more underactive areas of Life Stages. It was a bit more busy prior to the upgrade to CF2, but even then not enough to warrant a new subforum for LDRs IMO.
Just my 2 cents. On a side note, I think having seperate engagement/wedding subforums should be all together eliminated or at least combined

but I suppose that's for another topic.