Gift for Doula?

Emma • Mum to Harlen Jane🌷July 6th,’18 & Nolan Stone 🍭June 28,’19

Would it be appropriate to give our doula a small gift after the birth and postpartum visits as a Thankyou for supporting us through a very new and challenging experience? I know we paid for their services, but you kindof develop a bond with this person. What would be a good small gift?