Tragic heroine was younger it seems without Romeo (6)

I believe the answer is:
isolde
'tragic heroine' is the definition.
'isolde' can be an answer for 'heroine' (I've seen this before). I'm not certain of the 'tragic' bit.
'was younger it seems without romeo' is the wordplay.
I cannot quite see how this works, but
'was' could be 'is' (being is a kind of being) and 'is' is found within the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found in the answer.
The remaining letters 'old' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for isolde that I've seen before include "Tristan and ... (Wagner opera)" , "Irish princess" , "for Tristram" , "heroine (sic)" , "Wagnerian heroine" .)
