I would strongly suggest you take the bow to a GOOD bow shop and have them inspect it
45 bucks sounds CHEAP to me, meaning it could be a very low end bow, and or in bad shape
a few dry fires will do a hell of a lot of damage to abow that the naked eye cannot see

I kow money is a issue for most folks, but to me, for starting a kid off with a bow with questionable history sounds like a possible problem
be different if you knew the guy and history on the bow

but to me, new strings and cables would be a MUST do deal
and then when you add in teh cost of them, the bow and well, bew bolts ,
what your spending you could get a new bottom end X bow, and know its safe

to me, I just wouldn't risk a injury on a new kid
seem to me for kids to stick to the sport anymore the whole deal had to be enjoyable

not knocking a deal if its one
just something to think about
once you add up all the things , a new one sounds like a better investment in my eye's

Cablea's bargin cave always has tons of either out dated left over model x bows or trade in very cheap

seen brand new whole packages bolts head bow quiver for like 200 bucks, and thats brand new everything!
used one's for less

just a thought!