Oh hun! It's not that she doesn't love you anymore, but it's more than Nan probably makes it a pretty fun day for her kwim? We're just boring old Mum, but Nans are really fun and do things that are different to what we do during the day. I know it doesn't make your heart hurt any less, but it's great that she is forming this wonderfully close relationship with her. Maybe you could try some distraction while your Mum leaves so she doesn't get so upset? My mum used to have to do it with me when my nan left after a visit as I would scream bloody murder - she even had a copper who lived a few houses down come and see what all the commotion was one night LOL.