Break barrel style rifles will be VERY difficult for anyone but a semi fit adult to use with any regularity.
Spring air rifles in general are notoriously difficult to shoot consistently due to one's grip on the rifle and the rifles natural vibrations during firing. They are very frustrating at first. To master them you tend to develop some very bad habits, particularity overly loose holds (much of the exp. gained doesn't translate well into field shooting). Im not a big fan of springers.
Look at the Benjamin 392 multi-pump, they are just over $100, well made.
A cheaper alternative that will group about as well is the Crossman 2100 multi-pump. Both rifles require 0 CO2, nearly 0 maintenance, and can be pumped all day by an 8 year old.
If your budget could swing it one day.....Im in love with my Airforce Talon SS.... shoots 1/2"-1" groups at 70 yards through an integral Shroud that is so quiet...its just sinister
Used they can go for just over $300.