Any experience or advice for electric recliners or electric adjustable beds? Also, any tips for seeing if Medicare will pay for the bed?

Check out Spinlife on the internet. They have so many sizes of lift chairs, some even child-sized. Talk with a specialist to discuss her specific needs. Look for a bed that can be really close to the ground. She should be able to sit on the side of the bed and have both feet touch the floor (we should all be able to do that). I am 5'2" and use a really low bed frame for my own bed. Before the really low bed frame was made, we put out mother's electric bed off the metal frame and put it on 4X4's. She had fallen trying to get in and out of bed, but once we dropped it, that didn't happen any longer. The medical supply stores and catalog stores carry nice-looking, liquid absorbing, washable velvet chair pads that are large enough for the full chair seat and don't slip like the disposable bed pads. My parents found them really easy to use.

Call or look online for medical supplies that cover small or petite lift chairs. The supply company will know if Medicare part B, which covers durable medical equipment, will cover the chair. At one point Medicare only covered a portion but rules change. The doctors prescription would have to be written correctly. The medical supply would know what is needed. I would try to find a local supply company as they would be able to deliver and adjust and repair or replace equipment as needed.
I know medicare does cover beds. Again a good resource is a medical supply and you will need a doctors prescription. They dont all carry the same products so ask detailed questions on demensions and adjustments. The first company I worked with delivered a manual adjustment bed. I sent it back and went to another company.
If you find a good medical supply and give them your doctors name and phone and fax numbers they can expedite for you.

You can find online replacement chair legs in a shorter length. Also a wood worker could shorten legs for you. Due to the pain in her knees my dad had to raise furniture to a height that was easier for my mom to sit and rise from. In later years she used her wheelchair when she sat at the kitchen table. Otherwise she used a lift chair. Her hospital bed was too high for her the last year or so. We had to remove the rollers. That would be the problem for your mom. The beds will probably be too high. A low profile twin bed with a good mattress and waterproof mattress cover might be better for her.
Frequent trips to the bathroom and proper disposable underwear would help save the furniture as well as protective pads. With knee pain your mom may be putting off those trips. So a bathroom schedule may be helpful to get ahead of accidents.
I hope this helps.

If she qualifies for a "Nursing Home Medicaid Waiver" That is one that will provide Medicaid in her home Giving her Everything she would get in a Nursing Home, nut letting her stay in her home...If her Dr writes a prescription that is is medically necessary for her, yes she will get it at no cost to her. And depending on what state you live in it may go by another name, and they may tell you there is a several year waiting like but you say, " fine that is ok, I want to get my mom on it, and fill it out, do her interview if you are her POA.....or she can do it if you are noe, and there you go. Now if she has too much money or assets...get with a ELDER CARE ATTORNEY, to help her make a plan to distribute it over the next 2 years properly so Medicaid doesnt get it or disqualify her. Dont let them tell you that they will help her distribute it....YOU get someone on YOUR sided to help and if your Father is still alive that is all the better they can retain much more assets that way. Wishing you much luck, Blessings, and be Healthy during this time of pandemic!!