Hi there, technically, this entry is allowed in the W & A sketch but you will need contact information. I would suggest calling the clinic/hospital first, as these hours may be verified if this is its own section, so you will need to include the contact details. Remember that you have only 15 activities, and if you have other, more recent clinical experiences and shadowing, it would be better to include those. You will also need to write out your roles and responsibilities and any major lessons learned, so if including this, I suggest reflecting on how this activity inspired you further (perhaps it was an inspiration to continue on the medical track, as it happened so early).
However, similar to what others have suggested, you may want to include it in your other shadowing experience. I you do that, you can show how you were inspired and then explain the main lesson learned from the more recent shadowing.
Best of luck!