Part-time in-home sitter for two toddlers (3 and 1.5)

Young family of four living in sterling va. Theo (3) and Lily (1.5) are the stars of the show! We are looking for an enthusiastic person to play with the kids in the home and backyard, change diapers as needed, facilitate snack time and nap time as needed. Right now our need for a babysitter is infrequent and on an ad-hoc basis, but we are having twins this summer and are open to exploring a more consistent babysitting services (example: 2-3 hours daily or 4-6 hrs every other day). Our oldest (Theo) has a speech delay and is working with a speech therapist - whoever works with us does not need any special training but must be prepared to be patient with his communication skills, which are a work in progress!