She's like Don and Shannon (4)
I believe the answer is:
lena
'she's' is the definition.
'don and shannon' is the wordplay.
I cannot really understand how this works, but
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
The remaining letters 'lea' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'like' acts as a link.
Can you help me to learn more?
(Another definition for lena that I've seen is " River of Siberia (4400 km), the world's ninth longest".)