Armbars and Triangles....OH MY!!

Somewhere in the very beginning of my training I think I missed out on some key ingredients.  You might ask what could that possibly be.  Well, let me take you back in time...June of 2010...I was still very out of shape and my flexibility was horrible (and I do mean HORRIBLE).  I felt like the fat nerdy kid on the playground.  So the first move I ever got taught was your traditional armbar from mount.  Easy enough, right?  Not!  At that point in time, my knees were so stiff and inflexible, it was almost impossible for me to even attempt the armbar.  I felt like a complete failure.  So, I never even tried to armbar people, ever.  Then, there was the closed guard.  Everyone loves to play closed guard...not me.  I am 4'11" and fluffy.  Not the best position for me to be in.  I most likely will never be able to close my short legs around you.  So, you guessed it already, I never even try to put people in my closed guard (halfguard, yes, closed guard, no).  Needless to say, side control and north south have become my best friends (my go to positions).  I feel comfortable there.  I feel in control there.  I don't have to worry about my knees or my short legs.  But what about all those magical armbars and triangles and such.  A girl dreams about being able to do that sort of stuff.  Don't get me wrong, I love my bread and butter choke, but pretty much everybody knows that's my go to submission and they are ready for it.  So, my dilemma, how can I start to roll differently.  Get that old lady mentality out of my head and off the mat.  A good friend has been working with me and he absolutely hates for me to say that "I can't do that".  And I guess he's right...everything we do in jiu jitsu, I can do, I just have to figure out how to make it my own.  Plus, the unthinkable happened a few weeks ago.  Same friend taught me an armbar from SIDE CONTROL.  I can't tell you how happy that made me.  My go to position + armbar = PRICELESS.   Now triangles...I'm coming for you...this little old lady wants to be able to triangle someone in a live roll before she's completely gray and has grandkids.