Thanks for the comments.
I have been thinking about this a great deal and it seems like unless there is something manufactured specifically for this purpose (which I have not been able to find) there is really nothing I can safely do about it.
To address some of the concerns about the kids.... My kids NEVER swim without an adult being in with them. Doesn't matter if it is a public pool, friends pool, neighbors pool. They are WAY to young for that. My orig question was in no way to sub for me being there. It was solely to help my daughter overcome her fear of the water being too deep which may keep her from getting in the pool at all. She loves to swim but will not use the neighbors pool because she can't touch bottom and is scared.
Thanks for your concern though.

Swim lessons are a good idea. Believe it or not I didn't really see that option. I believe that would go a long way in helping my daughter. I think I will do that.
Thanks.