The 1930 census shows Samuel age 41 came to the U.S. in 1907 and Mollie age 47 came over in 1903. They were married approximately 20 years. Just as you say they were living in Hatboro.
The 1920 census has them still living in Hatboro with the spelling of Willmer (may be a deciphering issue rather than spelling). This time Mollie claims she came to the U.S. in 1901, but both seem to have been naturalized in 1917. You might try to get their naturalization papers which might be at the Bucks County Courthouse or perhaps Northampton County Courthouse (read on).
There is a WWI draft registration card for a Samuel Willmer/Willner who was born Dec 3, 1888 in Belostok, Russia living in Easton and he has a wife and three children. He may or may not be the same person.
The 1910 census shows a Rubin Levine age 27 and Mollie age 26 living in Manhattan, NYC and were married about 1 year. However it shows he came over in 1895 and she in 1896. So it might not be the right couple.
Some of these records you can see for free at labs.familysearch.org and Ancestry.com. For those you cannot see for free check with your local libraries to see if they have Ancestry or Heritage Quest.
You might also try to get their death certificates and obituaries.