Just my $0.02 worth....
Contrary to what was posted by 'djdj', yours is NOT a simple matter and you might put yourself in a VERY illegal position if you follow his/her advice. Do NOT call the police and have the landlord charged with Trespass!!!
Here is the situation as I see it....
1) You have a lease in place. You need to read it and see what rights each of you have. Obviously, you have paid the rent late twice. In most residential leases this is considered a breach and could allow the landlord all sorts of things (accelerated rent, penalties, termination of lease, etc.). You need to see what your lease provides.
2) There is no 'statutory' provision for "I paid the late fees, there was no breach". Again, you need to read the lease.
3) Again, most leases provide the tenant with some 'protections' in the event of landlord 'abuse'. An example would be a requirement for 30 day written notice of termination. Again, you need to read the lease.
Bottom line.....
The landlord can do anything that the lease allows, and you can prevent the landlord from doing anything the lease does not allow for. If the landlord has the right to enter the property for inspection/maintenance (as most leases do), then he/she has every right to be there and you would be in deep 'do-do' if you tried to have her arrested for trespass.