Thank you for the reply.
I have an interesting update. I just found her in my garden, but she's being shadowed by this other feral cat constantly. Where ever she goes, it chases her. I walked up to the feral cat to sort of shoo it away, but it hissed back and doesn't run away, it just sort of backs off. Then as my cat walked away the feral cat sprinted around me and went straight for my cat. I then attempted to spray it with water, but with being so close to my cat, they both run off. Npw that it's pitch dark, I can't see anything and feel helpless.
I'm sure I'm not the only one to have gone through this as a cat owner, I'm sure many peoples' cats have experienced this. What do cats usually do? Will this cat continue to stalk my cat? I want her in before we go to sleep tonight, but it's looking highly unlikely. Will this cat eventually let my cat go? My mum is getting extremely stressed by the whole situation, as am I.