an immigrant petition has been filed for her. If she lies on her non-immigrant visa petition and says it was never filed for her, she will be permanently banned from entering the US for lying to the consul about immigration benefits.
See, if you honestly show how many, what kind of relatives and which status they are in in the US - a consular officer may deny a NON-immigrant visa because you couldn't prove non-immigrant intent. You will be able to get your immigrant visa later on.
If you lie to the consular officer in regards to your immigrant visa petition or a lot of other eligible facts, you will get a permanent ban on ANY visa. Now, is it worth it to you? you decide. But do NOT advise other forum members to do the same.