Best 9mm for a first-time concealed carrier with small hands?

For small hands the gun that fits matters more than the brand. The three I put in students' hands most are the SIG P365 (and P365 X-Macro if you want more rounds), the Glock 43X, and the S&W Shield Plus — all slim, 10–15 rounds, and easy to conceal. The single biggest thing: go to a range that rents and actually fire a few before buying. Check that your trigger finger reaches the trigger cleanly and your thumb can hit the mag release without breaking grip. A gun that fits, you'll carry and practice with.