Considering that according to the article she is "being held on suicide watch at the Cheshire County Jail."

It may indeed be a case of "negligent homicide" and not willful malicious "murder". So I say keep the lower negligence charge for now (they actually got it correct on this one and didn't just give her a $100 fine for "unsafe passing" or some other nonsense) and then both investigate and interrogate her thoroughly to see if any evidence can be found for stepping it up to a murder charge (could be second degree murder while angry and drunk considering there was possibly a fight between them before he left, I'm not discounting that possibility, just saying find the evidence and/or get a confession first before upping the charge.)

Either way at least get her on the "negligent homicide" charge and for goodness sake get her out from behind the wheel on the public right of way. Time for her to start pedaling a bicycle back and forth rather then driving a multi-ton high speed vehicle that can be a weapon of death and destruction. She has proven she can't handle that responsibility.