What is wrong with my tortoise?

Hi, I am writing on behalf of my mum. She has had a female hermann tortoise for 45 years (tortoise is about 45 years old) and she has recently layed eggs. This is something she does every year, even though there is no male, therefore the eggs aren't fertilised. After going to the vet to help her lay the eggs she has become very restless and agitated. She doesn't stop marching around her enclosure and she has even escaped a few times. We constantly have to check to see if she is still in her pen and it is getting diffcult. She has not eaten for a few weeks now (before and after laying eggs) so we are getting worried. She always has fresh water in a shallow dish, we give her the correct foods, she has plenty of room to walk about and has a house to go in at night so we can't think of anything that would be causing this behaviour. She has not done this before, so any advice would be really appreciated. Thanks.