Hi Neil, Roberta Flack's version of "Killing Me Softly..." (recorded November 1972, released on single January 1973) was itself a cover, of Lori Lieberman's original version, also on Capitol. This Anne Murray album debuted on Billboard's Top 200 Albums chart in late April 1973, suggesting a release date in early April or even in March, so either Anne and Brian Ahern were very quick off the mark in recording the tune whilst Roberta's version was still on the chart, or they covered it independently some time before, possibly as a result of hearing Lori's album in Capitol's US or Canadian offices. Either way, Lori was probably not best pleased at seeing two covers of one of her recordings becoming more successful than hers (Roberta's #1 single and #3 album, and Anne's #39 album), whilst Lori's album went nowhere (although her next album, BECOMING, did manage to reach #192 later in the year).
Considering that the title cut, Danny's Song was first issued in 1970, Capitol must've been "dragging the chain" to get an album out around that song, notably because a few of the other cuts are of later vintage(including the Roberta Flack cover[A2], which Flack herself didn't record until at least 1972).