I think it's gone a bit too far. I'm sure I read somewhere that it's not the only job that she has got turned down for (please correct me if I'm wrong).
Salam
One might also think that at only 18 years old, one could be being turned down for jobs for a variety of reasons (lack of experience being a good one). Or if she has gotten turned down for a bunch of jobs, maybe she needs to re-work her interviewing techniques.
At 18, if she sues this woman (whether she wins or loses), it will bring a lot of attention - then who do you think will hire her ever? No one - they will be afraid she will sue them if she is not happy! And win or lose, it will cost both of them a lot in attorney and court fees.
This is different than the sister who posted in another area about her problems with the manager at the wal-mart that she works at - the first being that wal-mart is a huge corporation, not a single lady running her own business.
We as Muslims need to look at the full picture. Imagine you own your own restaurant (halal of course!), and your chef brings for himself a big huge pork sandwich for his own lunch? Or your waitress ends up being an unwed mother? Your cleaner is a hindu? The ways laws are, you can't discriminate and fire these people, or even refuse to hire them, based on this information. You can't advertise and look for ONLY Muslims to work for you - even in the US, churches who hire workers cannot require that the person be of the same religion. You can't tell your cook not to bring pork because then you are pushing YOUR religious beliefs on him - can't fire the unwed mother for having sex outside marriage because it would be enforcing YOUR religious beliefs.
So we need to be careful and choose our battles - I agree with the poster who stated that some MUslims seem to think they are being discriminated against any time somethng doesn't go their way. No one said life was fair or a bed of roses - we all know that Allah is testing us every day. Stay strong and deal with it!
Humbly
Lana