Grandma has not been able to walk for approximately 3-4. She eats less and has lost a lot of strength what can I do to help reverse this?

Has she been to PT? That may help. You can take her outdoors in a wheelchair, she may never walk again, my step father is in a wheelchair, he goes outside all the time.

She may not ever walk again but that doesn't mean she has to spend her remaining days in bed. My totally immobile mom spent part of all her days in a wheelchair, because she couldn't sit on her own she needed a tilt in place model - these are expensive but are available second hand (if you go that route do have it adjusted by an occupational therapist). Getting her out of the house and into nature might present another challenge if your home isn't accessible, but there are ramps, lifts and disabled transport services. If your grandmother had any ability to bear weight she can be transferred to the chair with help from you using a stand and pivot method, otherwise there are lifts that can be used.
When it comes to her appetite - there are many, many supplements that can add calories and nutrients, boost and ensure are two that are often recommended.

All of this is possible but takes effort and money, do be honest with yourself that you aren't confusing her true needs and desires with wishful thinking.

Christy, how old is your Grandma? I'm assuming she's on Medicare. Has she been in rehab after the strokes? Or ever had physical therapy? She should want the rehab herself, you can't want it for her. When my 80-yo+ MIL wouldn't get out of bed after going into LTC, we tried everything to encourage her, even creating incentive charts and goals, to no avail. After 3 long years the new facility we recently moved her to was able to coax her to at least get transferred into a wheelchair and taken to meals. She recently went on an outing to a llama farm and we were blown away. You don't mention how long its been since she's had the stroke but besides trying to incentivize her (but not drive her nuts by harping on it) she may just need time to adjust. Any further info you can provide will be helpful for recommendations. Blessings to you both!