My dog randomly doesn't have the confidence to jump on my bed anymore
As of maybe last week, out of nowhere, my dog started struggling to jump up on my bed. She'll jump and lean up against the side of the bed, standing on top of her two hind legs, and cry. Eventually she does jump up on her own, and doesn't indicate any pain while doing so. But it takes her SO long and for minutes she'll just keep crying and leaning on my bed trying to get me to lift her. I think it's a behavioural problem but it's really strange.
I do not understand why this has suddenly happened? She's never had an issue with jumping up on the bed in the past, this is just so random, but I'm scared something is actually wrong and causing her to do this. She still can jump up on the bed - she's just extremely hesitant to. The only other thing I can think of is that lately (before this started) she'd been jumping on my mum's bed and the couch, and my mum would scream at her to get off. But it seems weird for her to now be scared of jumping up on anything since she literally sleeps on my bed and know it's a place she's allowed.
Any ideas? Is this just a random anomaly or something I should actually worry about? I can't really take her to the vets because my mum hates her and wouldn't want to spend money taking her to the vets for something she sees as no cause for concern. I also don't want to start lifting her because I don't want her to get used to not jumping to get on the bed - because I want to make sure she still can jump on her own.
Also my dog is turning 12 this June.