I think your version suits the images much better, but... Did Achilles ever get married?? Maybe it's a case of Telephus chatted up Achilles' mother and got knifed.

If it had been a pretty boy rather than a woman, the intepretation would have been much more credible. Telephus chats up Achilles' boyfriend and gets knifed... Or did the Romans do some swift gender-bending in order to make the old stories less 'Greek?'

At the time, I was scratching my head, because I'd never heard of Telephus...