An attacker we haven't considered who is related to Cindy.... (Theory)

Cindy Jnr.

She left the square believing her mother died during childbirth. When it was revealed she was in fact alive, Cindy Jnr had broken up with Liam and went travelling.

Weeks later we then see Cindy meet up with Cindy Jnr off camera, and she says the meet up did not go as planned and Cindy wished she had just stayed dead.

Later on, she sends Cindy a heartfelt text with a heart emoji. It's then Ian says he persuaded her to do so.

Maybe she's been in touch with her siblings Anna and Gina, and has been kept up to date with her train wreck of a mother.

It has been a long time since we have seen Cindy, but she has had a recent bad break up. Could this be the result of violent behaviour on her part or something else that could lead her to trying to kill her Mother.

Thoughts?