The healing of Jairus’ daughter is recorded in Mt 9:18–26, Mk 5:22–43 and Lk 8:41–56.

Bart Ehrman sees a ‘clear contradiction’ between Mark’s account  and Matthew’s.  The former has the daughter on the point of death; the latter has her already dead.

In response: It is quite probable that Matthew’s version is a simple abridgement, with consequent telescoping of detail.  (Matthew’s account has 9 verses, Luke’s 17 and Mark’s 23).

Sometimes, in the Gospels,

‘a passage may be so abbreviated that it seems to contradict a fuller parallel. Mark has Jairus and his companions come to Jesus twice, once to tell him of his daughter’s illness and once to say that she has died. (Mk 5:21-43) Matthew so compresses the account that Jairus comes only once and tells Jesus right at the outset of the story that his daughter is dead. (Mt 9:18-26) This type of literary abridgment was common in antiquity and not perceived as misleading or in error (cf. Lucian, How to Write History, 56). Similar telescoping appears in Matthew’s account of the withered fig tree (Mt 21:18-22; cf. Mk 11:12-14,20-21) and in Luke’s account of Jesus’ trial before the Sanhedrin, if Luke is not in fact using a different tradition altogether, rather than Mark (Lk 22:66-71; cf. Mk 14:53-15:1).’ (Blomberg, DJG)

Michael Licona (Why Are There Differences In The Gospels?) similarly posits that Matthew has compressed his account.  Lydia McGrew regards this as ‘fictionalising’ the account, and prefers to explain the difference by some form of harmonisation, but, on this occasion, I find her suggestions unpersuasive.

Bill Mounce notes that when Jairus left home, he knew that his daughter was on the point of death.  Therefore, it was reasonable for him to suppose that, by the time he had reached Jesus, she would have died.  The news that she had, in fact, died (Lk 8:49), was not therefore a surprise to him.