Patch small holes in an internal stucco wall
Matching the texture of an existing surface (any textured surface, not specifically stucco) is an art form that takes years of trial &amp; error experience and rarely if ever looks exactly the same.

The composition/material used is not an issue considering the (small) size of the repairs you describe. Stucco can be textured infinite ways (sand finish, spanish lace, rough, etc.) and you did not describe or attach a pic depicting yours. Your best bet is to experiment (on a sacrificial surface) with different materials/products: mortar applied with different techniques, stucco patch, acoustic ceiling patch, drywall mud, plaster with sand added, etc. The options are limitless, start trying.