Shawhughes has been described as the former nanny to the two young children Hawke has with his ex-wife, actress Uma Thurman.
The insider told People Hawke and Shawhughes are expecting a baby girl. Hawke's representative confirmed in January that Shawhughes was pregnant.
Thurman recently announced her engagement to Swiss multimillionaire Arpad "Arki" Busson.
She and Hawke broke up in 2004 after seven years of marriage.