It's rare for a ball to be pulled @ 10U Rec. If it is, chances are there's already a runner on 1B anyway, so having a good 2B means the throw or underhand toss from the SS won't be treated like a live grenade.
In 10U, you're pitching from 35', not 45', which I believe is the standard LL baseball distance. Add in the bigger stride (well, maybe not right away - but probably by 12U), the pitcher is going to end up even closer to the plate. That's just too much distance to cover to make it to 1B in time to a) beat the runner and b)reach the bag, stop, turn around, and await the throw.
You're starting the same way I did - "No coach, no team". Here I am 5 years, and a combined 14 seasons of Rec/All-Stars/Travel later, and I'm still only at the 10U level with SOOOOO much more to learn. Really - thanks for volunteering, and welcome to the addiction known as DFP.
Lastly - coming from the "baseball world", and I'm surprised no one's mentioned this yet - don't let anyone tell you there's a difference b/w the baseball swing and the softball swing. A good swing is a good swing. Round ball, round bat. Same plate. Same strike zone. If they don't believe you, tell them "That's what Sue Enquist says". If they need to ask who she is, take two steps back, just in case their ignorance is contagious.
Good Luck!
Gags
Our 10U rec has coach pitch relief. Girls pull the ball off coach all the time. But yeah, if it's girl pitch only then fewer balls go to third for sure.