Context. Characters A and B have just gotten defeated by younger character C. And it has been about a year or so since they last met.
My problem in general with A and B is that they seem to tent to really colloquial language, especially A.
But anyway, first of, the problematic bit is そろそろキツいわー. I think キツい is きつい which was for some reason written using katakana. わー is likely some sort of untranslatable exclamation. My problem is そろそろ + きつい since it isn't excatly logical to say slowly formidable. So as of now I'm translating it as:
This young girl is steadily becoming formidable…
but I'm not 100% certain.
For the B's dialogue, 年だかんねえ is problematic. After some digging I was able to figure out that 年だかんねえ= 年だからねえ. So I'm thinking that she MIGHT be saying that their defeat and growth of C is because it's been a year. あたしたち is probably there to add that it's been a year for them too (since they were retired for that time). ねえ is just there to make it rhetorical. SO for now the translation is:
It’s been a year for us too.
So basically the question is am I right? Where am I wrong? And is there any special meaning behind using katakana instead of hiragana for キツ.