If she or you doesn't move after 3 days, they must sue you in eviction court and there will be a hearing. Keep in mind that costs rise as time goes on.
You are still required to pay rent. Under most leases, you may be held jointly and severally liable for the rent, even if you didn't sign the lease. I would contact the landlord and try to work something out. Explain that you aren't on the lease, and that you didn't really understand all the legal ramifications, but you are willing to pay whatever rent you owe directly to the landlord and ask for 30 days. Sign something that you agree to this. You don't want this on your record, either a judgment or a eviction.
This is general legal advice intended for informational purposes only and does not create and attorney/client relationship. If you wish further advice, please contact an attorney of your own choosing or you may contact me for further advice and make other arrangements including retaining my services.