As grandchildren, how do we go about filing for guardianship?

Our g-ma is 93 yrs old w/Dementia & Diabetes, she is currently in a nursing home per her physician due to her needing daily wound care, she has now been there 13 months...Our biological mother whom has never been there for us nor our g-ma is now, after all this time "taking interest in her care." She is extremely deceitful and knows people (ex: Sen. Lucio). She has recently filed for "next of kin" which he advised her to do in order to keep us from being so involved,giving her the only say so as far as our g-ma's medical/financial support goes. This is hurting her bc our biological mother has now changed all of the contact information, current Dr's and started cancelling her Dr's appointments which are critical for her wound care...(ex: our g-ma had a fall a 5 days ago, we were not contacted to go comfort her, but our biological mother whom lives 5 hrs from where our g-ma is was called, she advised the staff to sedate her and put her to bed- whereas normally either my sister, myself or one of my brothers would be called and we would go right over to make sure she was ok and stay the night with her, instead we found out 2 days later by a nurse after we asked why she seemed different). None of us children speak to our biological mother bc she has done us (g-ma included) so much wrong. Our grandmother raised 6 of us by herself as our grandpa passed away in 1978. She is such a wonderful,fun loving, caring person whom deserves to be taken care of during her elder years, she cared for us & now it's our time to do the same, unfortunately she will not have the same nurturing care from our biological mother,her intentions are not as ours are. She is already inquiring on removing our g-ma from the nursing home and taking her to reside in her home 5 hours away as well as transferring her financial status to our biological mothers place of residency. Our biological mother is extremely unstable, unreliable,& untrustworthy, she is continuously being evicted, without electricity, & food, as well as hospitalized due to her "illnesses" (hbp;diabetes;hypoglycemia;strokes;heart attacks;panic attacks;etc.). We believe that by her doing so, our g-ma will not benefit from her current wound care and it may even depress her tremendously, we pray to God that this is resolved in an immediate manner in order to continue to love & care for our Amma (g-ma) til Our Amazing Lord decides, not in the hands of deceit. If anyone can please help us file the proper paperwork in order to continue to give our Amma (g-ma) the proper care she needs and deserves, we would greatly appreciate it...God Bless & Thank You all in advance...
Michelle Herrera-Baughman
brian.michelle10@gmail.com