How long did it take you to faster?

[indysteel]

That's pretty much all it takes. If your friends are faster than you, see if you can get one or two to ride just close to your speed or a little above, so that you can push yourself.

I have been tracking all my rides on both Map My Ride and on my bike computer. I have one that shows me overall miles, plus I can do trip measurements, including average speed, max speed, and trip time. MapMyRide includes my "stopped" times, while the computer keeps up with my moving time (stops when I'm stopped) - which helps me see data on my performance (I love data!)

You can do it. It just takes more time on the bike.

Yes, it does take time, but I'd reiterate that speed work and intervals won't be particularly effective without a sufficient base, which I'm not sure the OP yet has.

This article explains the concept, albeit somewhat superficially.

I know how frustrating it is when you can't keep up with friends, but I would encourage the OP not to elevate that goal to the point she disregards what her body might be telling her. Hopefully, her patience will be rewarded eventually.