Do you know how much your friend weighs, or at least what her hip measurement is? That'll give us a good idea of what her size may be. (It doesn't sound like she'd fit the description for plus size, but if she does, she will need to look for very specific brands/cuts, since very few of Denimblog's brands cater to plus sized ladies)
I would be very, very careful about skinnies on her, unless she wants to wear them exclusively with chunky boots (and, like me, she may have issues getting boots over her calves if she is a true pear. If her calves are skinnier she is likely a Bell: http://www.denimblog.com/c/a/the-12-womens-body-types-and-jeans-that-will-flatter-each )
I would definitely recommend a pair of dark wash, wide leg jeans (to wear with the highest heels she can walk in, if she has short legs--maybe a moderate heel if she is a leggy Bell), some bootcuts and straight legs as well, but definitely not a boyfriend style or a super-skinny. Also, if she shares my big butt/short legs combination, higher rises will be her friend (shortens the torso and also covers the butt!) If her butt is on the flatter side she may get pancake-butt from a very high waist, so she'll want a slightly lower rise.
Hope this helps!