Rosie,
Merry Christmas!
The advice Hear Again gave you on another thread about having an intergrity test performed on your daughter's ci, is very good advice and should be done before there is any further talk about surgery for a re-implant.
As for therapy, exactly how much speech and language therapy is your daughter presently getting and what does it typically involve? I will tell you as the parent of a ci child, implanted in 1989, re-implanted in 2001 and who will graduate college this spring and who knows hundreds of other ci families and thier children, that while S&L therapy is very important, most important of all is what you and your husband do at home with both your children.
If developing oral skills is important for your children then the advice I would give you is to take the lessons learned at S&L therapy as a starting point and then re-inforce them at home on a daily basis. Talk, talk, talk and then read, read, read to your children.
And remember that this does not have to be at the expense of your children developing signing skills as well.
Good luck,
Rick