Social Security, Immigration, Identity theft

Hello,

My fiancee in the past was a victim of identity theft. Basically, long story short, She came as an international student here for her masters in Boston, received a social security number, and later on had that social security number stolen alongside her credit cards by her roommate. She is handling things on this side with equifax, and will be filing a police report in person when we arrive to the states together in December. Her social security card and other intellectual property is still in the proximity of her roommate who stole her information, since he still with takes residency at the same address.

Now we will be getting married soon, and starting the process for her in immigrating to the states. She will be changing her legal first name and last name, applying for green card and residency, and since she was a victim of identity theft, we were wondering if it were possible for her in applying for a new social security number, so she could build a new line of credit which was untainted by the identity theft which she suffered to. We're talking about 30,000$ worth of theft and a series of 5 or 6 cards being opened under her name.

Now for the sake of her immigration process, should she apply for a new SSN and leave alone the old one by not reporting it, I mean ideally I would like her to be able to get a new social, build a new line of credit, without having to worry about her past identity theft from the time she was an international student.

Can someone please assess this in the most logical/rational manner for me, because she is a bit worried/confused. Ideally I would like to continue filing the police report against her old social being used for identity theft purposes, and apply for a new one meanwhile.