@dolly --I agree with @thejerrybryan as far as making 2 separate databases and keeping the original intact for a while at least–just in case something or someone is missed in the transition…
This link will tell you what will transfer and what will NOT on an RM 10 drop and drag…
As for splitting your database-- I’ve always have had separate databases on my lines BUT the split is at my parents-- my dad and his brother married mom and her sister–so for me it makes more sense-- I also include the parents of my parents in each database-- as for hubby, I did the same on his maternal side BUT on the parental side, I have different branches with some overlap-- just easier for me…
@MadDog’s suggestion of color coding ( and or making a group and color coding) is also excellent…
I would also suggest that when making hubby’s, you detach yourself from your parents and vice versa when you do yours–so that you all show up in in the family BUT that is up to you…
Once done, make sure you check to see if everybody transferred and that you don’t have any duplication.