A typical lease will also have a paragraph outlining when a landlord can enter the apartment. Once you have given her written notice that you intend to vacate the property, it is reasonable for her to be able to show it to other prospective tenants WITH reasonable notice and accommodation to you.
Landlord-Tenant law greatly favors the tenant in Connecticut, but the lease agreement governs what happens. If you would like to discuss this further, please give me a call at my office: 860-688-1400. I'd be glad to help you further
Not all the facts are here of course. If the landlord happens to find a tenant, then the "charges" will be minimal a landlord cannot charge for double rent
They can charge for beyond normal wear and tear etc.
In Connecticut, it is required that the landlord give you 24 hour notice to enter your apartment or a time that is mutually agreed by both landlord and tenant. If there is a emergency in the apartment, the landlord can enter at anytime. I hope these guidelines from the CT judicial website can shed some light on the situation. http://www.jud.ct.gov/Publications/hm031.pdf
As for the short notice, it is required to give 30 days written notice on a month to month lease or if it is different in your lease agreement. Make sure you send your landlord a certified letter stating you are moving out so you have good record. If your landlord does charge you, I would seek legal counsel.