Senator Kirsten Gillibrand’s presidential campaign on Wednesday introduced a proposal aimed at investing heavily in maternal and child health, adoption and in vitro fertilization, paid family leave and universal prekindergarten.

The proposal, which Ms. Gillibrand called the “Family Bill of Rights,” continued her campaign’s focus on women and families. On Tuesday, she was among several Democratic candidates who joined a rally outside the Supreme Court to protest new abortion restrictions that some states had recently adopted.

But Ms. Gillibrand, of New York, has struggled to gain traction in the presidential race, barely registering in many Democratic primary polls. She has also lagged in fund-raising.

In a statement, Ms. Gillibrand said her new plan, which builds partly on her previous Senate initiatives, “will make all families stronger — regardless of who you are or what your ZIP code is — with a fundamental bill of rights that levels the playing field starting at birth.”