Most feminine forms of male names look weird, and Jaocobina is one of them. It sounds funky-clunky, just like Cuthberta, Abrahamina and Benjamina. Don't give your child this name, it's a burden.
I'm adopted. My 'adopted' mother & father gave me the name - Jacobina. My dad nicknamed me Cobi. I should mention my adoptive mom is German/French & my dad is American. I'm a German citizen. I can speak fluent German, French & English/American. Unfortunately, most people mispronounce my full name. The proper pronunciation is Yah-Co-Bee-Nah via the German language. I go by Cobi, it fits my personality & is much easier for people to pronounce!
This name just looks and sounds very unflattering for a girl. I love the name Jacob for a boy, but why try to make a perfectly good boys name feminine?