the 37-year-old fashion veteran sported a tiny string bikini as she posed with her two-year-old son quinnlann clancy for a sweet snapshot , which she shared monday on her instagram account .
` boogie boarding with my baby , ' she captioned the image .
and online commenters could n't help but note how fit maggie looks only a few months after she and her husband alex mehran welcomed their first daughter into the world .