Can B1/B2 with approved I-30 be used to wait in US while processing?

[mattsuko]

My wife was petitioned by her US Citizen sister. I-30 was approved but waiting for visa number will take many years. She has a 10 years Multiple Entry B1/B2 visa. She is pregnant and planning to deliver the baby in the US. She will travel together with our minor sons aged 5 and 10 to the U.S. when she is due. Is it possible for them to stay in the U.S. and file for residency and stuff and wait there in the U.S. till the visa for I-30 is granted? Please help, we need advice on how to make them wait there in the U.S. while processing I-30.