Affinity's have big headstocks and 21 frets.
Pics would help.
The Affinity series strats are actually made of Alder. As for Agathis, it's very similar to basswood, so no probs there.
It sounds like you may have the Squier Strat, the one that came with the SE-100 strat pack. If so, I bought one a few days ago, and in the few hours I had before I tore it apart, I found it to be a VERY good little guitar 😀
edit: By the way, if it IS the SE-100 strat, then it's made of agathis or basswood.