grief over her boston

My best friend and roommate has just lost her Boston Terrier that we both loved and cared for. She was only 3 and was a rescue that came with( we found out 6 months later) with heartworms. We took her to the vet numerous times for treatment, but her little body and heart could go on no more. She died in my friends arms. She is grieving so badly,that I feel lost. I don't know what to do or say. She has been in bed for two days, crying. I know she needs to mourn, but she isn't eating nad it hurts me to see her this way. I deal with grief differently. I know that our little dog is in a better place, free of pain and can play and run. But still I feel lost. Can anyone help me? Any advise? Thank you, Jill