It's from a 2000 report, but still...
On page 4: The estimated rate for murder offending by women in 1998 was 1.3 per 100,000 & about 1 murderer for every 77,000 women. The male rate of murder offending in 1998 was 11.5 per 100,000, about 1 murderer for every 8,700 males.
Pretty ugly are the numbers regarding relatives, ugh:
28.3% of females kill their spouses, only 6.8% of males do.
10.4% of females kill their stepchildren or children, only 2.2% of males do that.