https://screenrant.com/new-girl-jess-day-zooey-deschanel-age-how-old/

Viewers met Jess Day in New Girl and witnessed many ups and downs in her life – but how old was Jess at the beginning and end of New Girl?

She might be in her mid-20's at the beginning until her mid-30's at the end, approximately, TBH, IMO.