If you got them from a pet store, odds are both are WC so it's totally up in the air whether or not they're related. If they are, there's no worries, just do a bloodline exchange with some other hobbyists every few generations.
As for age I'm not quite positive that they're both adults. Their telsons are a lot lighter-colored than my adult female's.
Also, don't worry about them being "fat." If a scorpion eats too much it simply stops eating.
