Cora, played by award-winning actress Ann Mitchell, appeared on the BBC drama for a guest stint in April as she arrived in Walford for Tanya's wedding.
During her brief stay on Albert Square, Cora quickly became known for her brash attitude and outspoken ways.
"We all love Cora here - actress Ann Mitchell could be one of the Walford greats," Kirkwood explained in an interview with Inside Soap. "She'll be returning late in the summer and is here to stay."
Kirkwood also promised that there is more to come from Tanya's troubled sister Rainie (Tanya Franks), who has stuck around in the area since returning for the wedding.
He said: "I'm really keen to establish the Cross women - Rainie completes the mix as the slightly broken sister who's one step away from a vodka bottle."
Jo Joyner, who plays Tanya, has previously said that it is "a real treat" to film scenes which focus on her character's family.
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