I am guessing that was an interview at the consulate. Did they mark anything else on the paper (blue one?) she received? Did they keep her passport?
The reasons for delay could be all of the above and a few more.. how long it will take? It depends on the reason and, sometimes, the particular consulate. Some are more strict than the others.
Does your friend have any feeling what it may be? She was the one there.. were they particulary interested in something?
We don't even know what kind of visa she applyed for, what papers she submitted, what was she asked and whst she answered...
maybe your friend can come up with a few ideas what may be the problem, so we can start from there.
At the end, sometimes the reason may be as simple as the person who can sign visa issuance was out for the lunch.
yes it was a consular interview, his son who is US Citizen petition her, i dont know what category it is. when i saw her she was also confuse and have no idea why they gave her a paper saying that wait until you hear from us, yes they have her passport but we dont have any idea what will happen if a person has recieve a paper like that?
what can she do about it? can she contact the embassy to ask question what she will need to do, how long will it take for the embassy to contact her, does she need more evidence of their relationship, is her document not sufficient enough for tha consul?