Guys, I was lucky to find one of the best companions in the female magician "Lila".

Since I turned into a Werewolf and therefore had to do that one quest with Aela - she's gone.
And she was not back at where I took off with Aela. Where can I find her again?

All the companions I had since then are crap and die way too fast.

Neither the Elder scrolls wiki, nor the UESP recognise the name 'Lila'....stupid question, but are you sure that's her name?

is it illia?
she is not able to be recruited again.

If you mean Ilia, then I think it may be that you cannot get her to follow you again, after she is separated from you. Might want to look that up though.

Here is probably where you found her:

Exactly! Thank you. But - why can I not recruit her again?!

Doesn't she return to the tower? Or she goes back there, but you can't recruit her again?

^ she returns to the tower, but theres a bug where she wont give you the option again.

WIKI : Currently, there is a bug in which Illia is no longer recruitable after you send her home. When you talk to her, she will respond with generic dialogue, (much like a guard), and you are unable to choose any speech options. A solution on the PC to this is to open the console with the ` key, select Illia, and type 'setrelationshiprank player 1'.

I lost Jenassa in the same manner, I found her outside the Underforge. If you still can't locate Illia, I'd check there. This won't necessarily get past the bug where she can't be recruited again, however.

Damn. I was going to recruit her in this playthrough. Good thing I'm on PC

thank goodness for console commands huh?