What is the name of your state? FL

My landlord made up claims about damages on the property I lived in which are complete lies. The building is an older building so many things have detoriated over the years prior to my one year lease with her. She is blaming me for rusty locks, loose outlets, and plubming problems. She sent a letter with the items and the amounts. I am going to send a demand letter and then initiate small claims proceedings to get back my money. My question is does she have to prove that I did this damage or is it upon me to prove I didn't do it? I took the apt in as/is condition, which is stated in the lease and these items were already in poor condition when i moved in. I accepted that since the lease was in as/is condition and now she is blaming me for things that were already broken. I have photos but photos unfortnately cannot show plumbing isn't working great or outlets are loose.
Also the prices she noted on the paper are extremely high - doesn't she have to substantiate the repairs with receipts - can she just make up the amount?
What do I need to do so I can win this case in court?

Thank you.