How much weight can a 13 H Welsh Pony handle comfortable?

Would a rider that is 5'4 and 125 lbs be okay for 2 hours every few days, or is that too much weight?

Here is a picture of a pony the size I am talking about http://www.chregliamanor.com/Sales/Images/Benny/BennyLeft2.jpg

Can anyone who knows the Welsh language suggest a nice, not too hard to say (for non-welsh) name for our soon to be born Welsh pony filly? preferably with the meaning... or maybe a website?