good morning and welcome to our cat forum we are always glad to have new members, I hope we can be of some help.
However I'm sorry without a Vet examination its pretty hard to pin point what the problem could be.
floppish and head tilting, could she possibly have been hit or kicked in the head?
these symptoms do sound to be neurological, but thats only an uneducated guess. there could be many reasons I'm sure. Do you think she has been drinking enough?..dehydration can cause many symptoms as well.
pinch the skin under her coat...it SHOULD spring back quickly(in contrast to holding the pinched position)
An 11 yr old cat is now a senior and requires an extra amount of Vet care to remain healthy, including possibly a change in her diet.
I hope you can find in within yourself to help your longtime companion, I know how it is when money is short, perhaps there is a Vet there than would allow payment to be made in monthly amounts...an exam and blood work isn't very costly.
the best of luck to you and kitty, please keep us posted with updates and any more questions that we maybe some help with.
Did you check her ears? Sometimes an ear infection or mites can cause head tilting. If there is a dark brown stinky discharge it could be either. You will have to see a vet to see what it is and get medication for her.
I second the above posts. Without a vet's examination we are just assuming and we definitely don't want that. The best thing to do here is to take kitty to the vet ASAP.