Solving Omlet Smart Auto Door Timing Issues with Alexa Routines

[Lucy V]

I have an elderly chicken who in the last year has slowed down a lot this year she has started to walk like a penguin with her bottom right to the ground and gets a mucky bottom very easily which has to be washed every so often. She has days where she will go right out into field and explore with the others and she'll have days where she will stay a lot closer to home in another small section of grass they've got which is understandable as she is old she sits down a lot and you can sometimes see her closing her eyes for a rest she has been doing that for about 2 months now but in the last 24 hours twice I found her on her side! We have a compost heap wich someone tipped something on and left and saw she got out of bed (she goes to bed early) but when I came to shut them in 2 hours later as it was nearly dark I found her lying on her side with one leg in air that's was shaking a bit I put Her back in her feet and it took her a moment then she went of to bed (they have to jump quite a bit to reach it so not sure if she tried to jump up and failed and fell or she managed and fell when she jumped down or just fell without even trying), I went down this morning to them out she is usually up but just waits to be let out instead of running around crazy to be let out like others anyway I had some snacks for them which I laid out before I opened the coop (they have a small outside enclosed bit as well) so they can see exactly what I'm doing the others were running up and down excited for snacks and when I opened door I saw She was on her side again but I'm not sure if she was knocked by the others (24 chickens) running up and down or if she fell but was in same situation as night before took her a moment but she quickly went off to get the Snacks (she is still very determined and is eating and drinking Any snacks I put down she Isn't afraid to fight the other off in her old age!!) 

what im wondering is this just normal for an old age chicken or is there a condition they can get wich usually causes this ??? Anything to be worried about or is it just part of her old age ??