Elizabethstudios has many types of nice sports themed fabrics. I did a swimming bag for my sis in law last christmas. The other sis in laws got tennis, golf and basketball purses.

Could you broaden it and go with a pool party theme? Pools, cabanas, swimmers, etc and perhaps a little something from her school or team? As far as the fabric, I buy a lot of fabric online - not the fabric stores, but on ETSY. When you know specifically what you want and only want a couple yards, it can be a great source. And, on ETSY, you are encouraged to have conversations with the seller so you can ask about the content and other questions you have. I have come up with some very, very odd prints to use as my base for specific projects.

What about a mermaid fabric - have seen several pretty prints. Guess it depends on how old she is.

I had some fabric that was all swimmers in it but don't have any left. Bought it here in S. Calif. the store is called M&L Fabrics in Anaheim. My son-in-law did the iron man so I found fabric with swimming, running and biking. The panels were separated by stars and it really turned out to my satisfaction and he just loved it. Don't have any material left so I could give you the name of the manufacturer sorry. The phone no. is 714-995-3178 they may still have some

Not sure if you're willing to consider applique, but there are tons of swimming related appliques. I had one I did of an old fashioned swim suit & flip flops & always thought it would be fun someday to do a quilt of ladies swimsuits over the decades.

Timeless Treasures has this swimming fabric that you might could use for backing.

https://www.baywindowquiltshop.com/g...ing-by-tt.html

Thanks, now I want to make myself something to remind me to swim more. I love the water, but just sort of "bicycle" around the deep end. Water aerobics class was too hard for me after a year off, but I should do some exercises and work up to 2 laps of easy swim strokes.