The way Obama Administration exploited loopholes in US law to create DACA, stop deportation of family members of certain immigrants in the country illegally, and give legal status to family members of US servicemembers, yet another new provision allows all those aliens who came to the United States from a country that participates in the visa waiver program to adjust their status as long as they are immediate family members of a US citizen.
What does this new policy do? You see if you are a citizen of a VWP country, you can enter the United States without a visa but such entry comes with many conditions, like the length of time you can stay and your inability to extend your stay or adjust status to another category (privileges that are available to aliens who enter with a valid visa). In fact, ICE can deport such individuals without even an immigration hearing, a privilege that is generally available even to illegal immigrants.
How to adjust status based on this policy change? This new policy is very limited in its applicability. In other words, you need to discuss this with an immigration attorney who will advise you whether you are eligible. The good news is that if you are an immediate relative (related by marriage or birth) of an American citizen, have not committed any serious crimes, and are not yet in deportation proceedings, you are very likely to be approved. The paperwork is surprising simple and among other forms would require USCIS Form I-130 and I485.