According to Watchtower theology, if you commit a sin*, you have to let the elders decide what to do about it, generally with a judicial committee.
If the committee decides that you are repentant for the sin, then you won't be disfellowshipped. If the public at large knows what you did, then you will be "publicly reproved", with an announcement at the Kingdom Hall. The other JW's can still talk to you, party with you, whatever. If nobody knows what you did (smoked a cigarette in your basement, for instance), then you can be privately reproved, no announcement is made.
Reproof will probably [always?] result in the loss of "provileges" like commenting at meetings, being on the theocratic ministry school, and the like.
If she's a strong JW, she's probably feeling VERY guilty about whatever she did. The elders would have laid it on very thick, so any support you can offer along the lines of "you're a good person" would be great.
*"a sin" here refers to "serious sin" like fornication, smoking, apostasy.
Dave