T.P.
Everyone grieves differently. but it sounds like it's been a few years and that may indicate something deeper than grief.
could it possibly be a misunderstanding and she's upset with you? sometimes during the grieving process little things other do during that time, since we can be very emotional at this time, little things can get blown into bigger things. that at any other time wouldn't be a big deal.
either way, i would say call her till she talks to you about this. or try to get a relative(her sister/brother or you sister/brother) to also call and/or go see her. i would keep trying. write a letter if you have to expressing your concerns . and if she still doesn't respond,,,, i agree with the other post. could be depression and she may need to seek a therapist. sometimes there is a stigma with therapy, especially for different generations.
maybe if you talk to enough people in the family-that she's also not talking to- they will come together with you to help her move forward.
good luck... email if you need to talk...
my mom passed away 15 years ago when i was 23 (she was 44).. my dad still to this day hasn't dated. and jokes that my mom haunts him..lol lol i hope he's joking anyway..lol
God Bless
T.