Am I Busted????

I was chatting with her, and suddenly she ask who is the person that I love.....
She asking because she read my post on messenger....

So I reply to her that the person who I love is her (and it's true)...
We have discuss about it very long time, and suddenly the reply said....
"This is her sister,not her...."

I was silent and can't explain anything...

Now, I still confuse..
Is that her sister or she just pretending to be her sister????