[@Deos Morran] Well I don't think any Turian could out-muscle a Krogan but a clever one can disable them if skilled and quick enough. 

Aegon is good in melee but he's one out of like a dozen people. 

Also keep in mind that the Collectors didn't attack any Turian colonies and that the Reapers were basically a myth until the war happened. Also she's a Lieutenant despite being relatively young and inexperienced in comparison to other Turians. It would make more sense if she got some officer training once she hit 15.