The calf was first spotted with its mother Ulcer last month, prompting Rockingham Wild Encounters to launch a competition for locals to name the baby.
Vaelen Hewitt died of Sudden Unexplained Death in Childhood (SUDC) last April at just two years of age.
More than 250 people liked the Hewitt family's suggestion, which said dolphins were Vaelen's favourite animal.
PerthNow Digital Edition.
Your local paper, whenever you want it.Get in front of tomorrow's news for FREE
Journalism for the curious Australian across politics, business, culture and opinion.
READ NOW"Since then dolphins seem to always be nearby and their playful nature and cheekiness reminds us of our beautiful little Vaelen," it said.