I am very glad to hear you came out of the situation OK. Our local trail is always so packed this is not a problem. My wife goes there to ride while I watch the baby. Sometimes I go and walk with Samantha while she rides.
I am a advocate of firearms for personal safety but in this type of situation it may work out to a disadvantage unless you just went ahead and fired at a nearby spot to scare the crap out of them. If they were truly agressive and clever they may be able to get your gun from you and then where are you at?But I would certainly admire a "packin momma" out on the trail.
Pepper spray or better yet a true teargas spray would do well. Soak them good with it. There are also some telescopic pumps out there that would give a good bump on the noggin.