Family Feud and Conflicting Trademarks

My family has owned a bakery for generations, known as Grandma’s Goodies. We never formally trademarked the name, but it’s been our local brand for over 70 Wordle Unlimited years. Recently, a distant cousin decided to open a rival bakery across town. They registered the domain name „GrandmasGoodies.com“ and are building an online presence that heavily resembles ours, including similar logos and branding. My cousin actually trademarked the name „Grandma’s Goodies Online“ a year ago. They claim this trademark protects their online presence, even though it shares a significant similarity with our established brand.
We’re worried about customer confusion and potential damage to our reputation. We don’t have a trademark for „Grandma’s Goodies,“ but we have common law rights due to our long-standing use. My cousin’s trademark seems specifically designed to target our online presence, even though their brick-and-mortar store uses a slightly different name. Do we have a case for reclaiming the domain name based on our common law rights and prior use of the brand? Does their „Grandma’s Goodies Online“ trademark hold water considering the similarity to our established name? What course of action should we take to protect our online identity and brand reputation?