Just a few thoughts on the font inspired by the coffee bag.
Having seen somewhat of how a font is created, I can't how
you would want to create one based on her handwriting
without contacting her. If the font were to be based on her
writing style, several examples of each letter would be
needed for comparison and selection of the 'right' letterform
to create a cohesive set.
If you are inspired and extrapolate the rest of the font out of
the one word; I say go for it. I cannot see any copyright
problems since you are creating the rest of the letters and it
will then be your intellectual property and you would retain
the rights. Ask her for her name and use that to title the font.
Depending upon the approach taken when contacting her
could determine what kind of compensation, ranging from a
use of her name up to monetary considerations, might be
necessary. Some kind of permission will then have been
arranged and copyright won't be an issue.