That is one lovely wall hanging. She should be ashamed of herself for even making an offer of $60.00, especially after you had given her a figure & her response was "ok, but I will probably pay you more than that". It is an insult. Having said that, shame on you IF you accept $60.00. She is obviously "in the dark" concerning how much material, stress & most of all the time & craftsmanship to make anything "handmade". Some people think "handmade" means less than perfect, rough, not up to store quality but those of us who know, are aware, that is definitely NOT the case.
Please do not sell it for less than what you had previously discussed.