I hope she never outgrows this, but one of Sabrina's best character traits is her desire to help. She will get in the middle of things and help out, even when not asked. It is such a wonderful trait, that we do whatever we can to cultivate that innate desire to help, even though at this age she is generally not actually helpful. We sometimes have to be creative to quickly think of a way for her to feel like she is helping.
Robby had to do some last minute plumbing while the cabinet makers were installing our new cabinets. Sabrina was desperate to help, so he had her hold the pipe while he put some purple stuff on it (I have no idea what that purple stuff does).