LONGER ANSWER: Buddhas can appear in whatever form is necessary to save sentient beings, so can certainly appear as mother. However, one has to be careful in designing one’s own Buddha because there is a substantial chance that one is just massaging one’s own delusions, desires, preferences, prejudices and so on. Iconographically, Amida figures are invariably male, but commonly a very gentle, soft male. However, if what was needed was for Amida to appear as a fierce dragon, I’m sure that would also be possible. Perhaps Amida has already appeared as the iconic figures of some other religions too.