Maternal grand daughter

Hello...my uncle expired 12 years back and her wife never in life took care of my maternal grandparents. It was my mother nd fathr who has been looking aftr them evr since i cn remember. 9 yrz bk v shifted onto my nana's house nd they were financially,emotional nd fyscly dependent on us. my maternal grandfather willed his property on my name. he died last year nd my grandmum z stl wd us. On getting ds info my uncle's wife shouted on my grandmum due to wich she colapsd nd v filed FIR against her. Then she sent a notice. Now v hv applied for probation. M aghast by the paper she hv filed where she hv mentioned dt she tuk all d care nd hr sons while dy didnt Even perform last rytes of my grandfather in a ryt manner!! What next step should i do......can my maternal grandmum help ? N yeah she hv thoroughly mentioned again n again dt i dnt hv any direct relation wd my mothers parent. I doubt ppl wd direct relatn evn knew my nana's full name. Mine z a genuine case...m fytng for my grandfather respect as she never gave hm any. KINDLY ADVICE. HOW CAN I STRENGTHEN MY CASE coz in 2 hearngs I KINDA LOOSING TRUST FROM JUDICIAL SYSTEM.(SIC)