I know what your mom is going through, because i have suffered with depression for many years too. Funnily enough it was my own mother who first recognized my depression....she said i didn't cry at all when i was a baby but now that i'm an adult i can't stop! That was at least 10 years ago and i started taking anti-depressants, however my husband was not as supoortive and made me feel embarrased and weak for being on medication, so i eventually stopped. The depression got much, much worse to the point of suicidal and the doctor had to have a serious talk with my husband to educate him on the disease. I have been taking my happy pills since then, and enjoying life.
I don't know your mom's age but i suspect she may feel a sense of shame or embarrasment for being on medication. If she has friends who know about her depression it may be a good idea to try and enlist their help in encouraging her to take her meds. It will seem like a total waste of effort to her for a few weeks, but if she persists you can promise her that she will see herself and her life from an entirely new perspective. She will become more confident, less isolated, more willing to "join in" and participate in life....like a huge dark weight has been lifted. With continued love, patience and determination from you and her friends she'll get to the point where she will want to take the meds, because she'll look back and realize how terrible depression can be.