HELP...Should I join or get in shape first?

This has probably been covered before, and I know what the "organization" would say, but I want the truth from those of you that are serious members. If I showed up, a 29 year-old mom of three who is about 30 lbs overweight but was once a good swimmer and has continued lap swimming all these years since high-school and would take her committment seriously, to your practice and wanted to join, how would you feel? What if you had to pass me by a few times because I slowed you down? But...at the same time you saw me working hard in my ability and pushing myself farther and fasther each day - would you snicker behind my back, would others? Should I continue swimming on my own and trying to get in shape before I join? It is ok to be honest. I would tell you the truth. And please, don't yell at me for worrying about what others think. Thanks everyone!