In the example, who do the pronouns she and her refer to?

For me the problem is "anaphoric" - delighted is not anaphoric - it is an adjective - and it is simply confusing to refer to it as an anaphoric reference.

She and her are anaphoric.

OED

Of, pertaining to, or constituting anaphora (sense 1b - see below); referring to or standing for a preceding word or group of words. Hence as n., an anaphoric word.

1914 O. Jespersen Mod. Eng. Gram. II. i. x. 247, I propose to apply the word anaphoric to one (or any other word) if it refers to some word already mentioned, while I say

1960 S. Stubelius Balloon 28 While machine was from the outset the standard anaphoric for the aeroplane in the press, apparatus was only occasionally used.

1b. Grammar. The use of a word which refers to, or is a substitute for, a preceding word or group of words.

1964 M. A. K. Halliday et al. Linguistic Sci. viii. 248 In English these [sc. non-structural features] include grammatical anaphora, grammatical substitution and lexical anaphora; the first is reference back by personal pronouns and by deictics such as ‘the’, ‘this’ and ‘his’; the second is the use of ‘do’ and ‘one’ in the verbal and nominal groups, as in ‘I might do’ and ‘a big one’; the third is the repetition of a lexical item, or occurrence of a second item from one lexical set.

The example is not particularly good either: Bold = emphasis; italic = de-emphasised.

1. Jane said she (i.e. emphasised = Margaret)’d been delighted long enough and Margaret offended her. her = Jane.

2. Jane said she (i.e. unemphasised = Jane)’d been delighted long enough and Margaret offended her (i.e. Jane).

In 1. the emphasis is on she, and the "offended" thus looses emphasis.