I don't think the suicide watch is meaningful regarding whether or not she committed willful murder or negligent homicide. In our local papers, suicide after murdering one's significant other is not a rare event, at least not out here in the domestic violence capital of the west.

(To clarify: Murders of spousal units isn't super common, although we do have two in the past two weeks in this tiny one-third of a million person county, but when such a murder happens it is quite common for the killer to attempt suicide, at least hereabouts.)