As families across the U.S. prepare to celebrate Mother’s Day this Sunday, Allison Stern is looking beyond the single day of appreciation. Stern just closed $10 million in commitments for her debut early-stage fund, Mother Ventures , which focuses exclusively on the mother as a consumer. “In the U.S., moms are responsible for 85% of household purchases and have $2.4 trillion in spending power,” Stern (pictured below) told TechCrunch. “The numbers say that moms are the buyers, and they really are a very unique economic engine.” Stern, a mother of two, is tapping into that spending clout by backing startups that reflect the needs of modern mothers. Since launching Mother Ventures two years ago, she has already deployed $4 million into 13 startups. Her portfolio includes Coral Care, which allows instant booking of pediatric specialists for children with developmental delays, and Tin Can, a  popular  Wi-Fi-enabled “landline” designed as a retro-style phone for kids.…