For reflections on the lack of a name for Simon's mother-in-law, see this sermon by Ray Barraclough: Women without names
The Seminar voted this core event (Jesus healing Peter's mother-in-law) PINK, while voting the narrative transition (vs. 29), GRAY. The commentary in The Acts of Jesus (p. 59) observes:
The evidence is overwhelming that Jesus was regarded as a healer during his public career. However, it is difficult to identify stories in the gospels that are reports of actual healing events. This brief vignette comes as close as any to qualifying as a report of an actual happening. The version Mark records lacks most of the features that are characteristic of stereotyped healing stories ... Further, there are no precedents in Hebrew scripture of which this story could be the imitation. And there are no allusions to stories involving Elijah and Elisha and no references to cures of this type in catalogues of eschatological healings such as we find in Isa 29:18-19, 35:5-6, 42:18. In sum, this simple tale appears to reflect the memory of a cure worked upon someone close to the inner circle of Jesus' followers; it does not appear to be fictive.