Roommate problem

[Sheree Young]

Not sure if this is the place to post my issue. 

I rent a 2 bed/2bath apartment in irvine,CA from a landlord in san diego area.

(Me and my old roommate are on the lease, currently with 1.5 month left on the lease)

Recently i had to replace a roommate, since my old roommate got engaged, and her fiancee wanted her to move in asap.

So I found this girl from craigslist. 

She moved in Mid Aug (our lease starts in the middle of the month).

Our San Diego landlord requires a deposit of (1month rent+$250) per person. So that's what i asked from this new girl.  

She asked me if she can pay the deposit in 3 checks, which i agreed(big mistake i know now). 

But it is now end of Sept, 5 checks later, and she still owes me $125 in deposit in additional to Utility for Sept $50. 

and She gets mad at me for texting her about paying sept utility. 

On top of the money issue. She likes to pile trash by the trash can, and gets her food/trash on the floors without cleaning them up. 

And again gets mad at me for asking her to take "her own" trash out on her way out of the apartment. 

I tried to talk to her face to face, but she said she doesnt like face to face, and doesn't like my texting either. 

I'm planning on asking her to move out by the end of me and my old roommate's lease. 

But i want to make sure i do everything by the books. 

(she didn't sign anything with me, or with the landlord, she's basically subleasing from my old roommate)

I know this is probably not a typical issue here. and I am largely at fault here for too trusting.  

Thank you for reading my post, any input would be helpful and appreciated. 

Best,