Development in the production of /r/ is attested in a speaker of Standard Southern British English (SSBE) between the ages of 3;8 and 3;11. The progression towards adult-like apical approximant /r/ is manifested along multiple dimensions and primarily involves a gradual raising of F2 and lowering of F3. In addition to changes in absolute frequencies of F2 and F3, however, we find that this speakers development involves general reduction in variation of her output, elimination of apparent [w] substitutions concomitant with increased labiodental realisations, and decrease of F3-F2 distance. This latter acoustic cue is worth additional exploration, as F3 may remain stable between perceptibly different outputs. Moreover, the data show that development of /r/ may include a shift in the relative salience of F3 by means of increase in that formants amplitude, again compensating for non-lowering of F3 to canonically /r/-like frequencies.