Can this index entry be corrected?

No, the index cannot be corrected; it is so old that the connection between the index entry and the image has degenerated into a vague "somewhere on this film".

The link you gave is to the image; the index entry is this: https://www.familysearch.org/ark:/61903/1:1:HWD4-58ZM

The group of profiles on Family Tree (https://www.familysearch.org/tree/person/details/9XQ1-RCK and her "parents") is also old data: it's the result of extraction-program-based entries in a preceding system on FamilySearch. These extraction-based profiles always follow the index, letter for letter, enshrining every indexing error.

What you could do is to attach the (mis-)indexed christening to the "tryptich", then correct the mother's name on her profile, writing a note somewhere (in the "reason" box, maybe, or in the attached source citation's "Notes" field, or both) about the error in the index and the correction you've made. (I'd have done all of this already, except I can't read the record even enough to figure out which of the several Trujillo entries on the page is her.) Normally, one corrects errors in the Tree by fixing the relationships, not by changing one person into another, but in this case, the incorrect profile is just a stub, with no data beyond the name, so it's easier to leave the relationships and just fix the name.