A nanny who is an illegal immigrant, Ms. Poo said, most likely does not have pay stubs or tax forms to prove she worked for her employer because she largely exists in “a paperless world.” She called on the senators to accept “proofs of presence as opposed to proof of employment” when it comes to providing a work history for domestic care workers — many of whom are female.

Another issue of concern is that immigration legislation that is likely to emerge from the Senate might eliminate the ability for United States citizens to sponsor their married adult children, as well as their siblings, on an immigrant visa. Currently, these two groups represent the third and fourth preference categories when it comes to family immigration, but there is some discussion that they might be reshuffled and ultimately cut during the coming immigration overhaul.

“Our family is what permits us to be able to set root and really begin to build a life in this country,” said Mee Moua, the president of the Asian American Justice Center. “If those two categories were eliminated, unless some alternative version was put on the table, I think that it would just unfortunately affect women and their families.”

Ms. Moua argued that large, extended families can be critical to helping immigrants become a productive and integrated part of American society.

“Family immigration is critical to our economy, and we know that our communities and all Americans benefit when we’re able to provide immigrants with an opportunity to set roots,” she said. “We know that siblings provide immigrants an immediate social support system, that is able to help them with child care or if they fall on hard times, or instances where they need some help to start a business. The family network is what has helped our immigrants, regardless of how you come to this country, survive and start a life in this country.

“Children will always be our children, whether they’re over the age of 21 or not.” she said. “For us to start to think about which members of our family we’re going to trade away is a dramatic and drastic departure from the core values of what has been driving this country since our founding days.”

Senator Jeff Sessions, Republican of Alabama, however, was not so convinced that all family members of immigrants deserved special consideration, simply because they have family in the United States.