Faldage and Jackie,

The problem here is that she is a member of a group of women, all of whom like football. She's not alone among those women in liking football. I wish I still remembered how to diagram a sentence. While the singular may be strictly correct (and I'm not convinced of that) the plural makes more sense, both in terms of logic and of proximity.

Here's what the AHD of English Usage has to say on a very closely related construction:

agreement by proximity.
Certain grammatical constructions provide further complications. Sometimes the noun that is adjacent to the verb can exert more influence than the noun that is the grammatical subject. Selecting a verb in a sentence like A variety of styles has been/have been in vogue for the last year can be tricky. The traditional rules require has been, but the plural sense of the noun phrase presses for have been. While 59 percent of the Usage Panel insists on the singular verb in this sentence, 22 percent actually prefer the plural verb and another 19 percent say that either has or have is acceptable, meaning that 41 percent find the plural verb with a singular grammatical subject to be acceptable.


http://www.bartleby.com/64/C001/060.html#SUBJECTANDV1