Originally Posted by dragonflysky
How old are your children? Are they old enough to tell you what they'd like to call other women in a relationship with their parent(s)?? Titles involving "mom..mum...mother..." can have a lot of emotional load attached that a child may or may not necessarily feel. I...for one...wouldn't want to impose the use of a title on my children that might imply or assume an emotional attachment.
If they do have an attachment similar to that with a parent, I've found that children can be quite resourceful in coming up with their own versions of "mum, mom, mommy, Mama Jane, meema....etc" to use. If the child is a toddler, you'll probably have to make the choice. I recommend it not be exactly the same as their other parent, however, unless the other parent is fine with that.
I also agree with this. Don't force it upon them, just let them develop a name themselves.