The hard-hitting plot, which has seen Ronnie Branning swap her dead child James with Kat Moon's newborn son Tommy, was originally tipped to last for at least a year after its details were first announced in November.
However, following complaints from viewers when the story went to air, it was confirmed that the matter would be resolved on screen earlier than planned.
In a new interview with OK magazine, Wallace - who plays Kat - said that it was the right move to cut the story short.
She explained: "I don't think it could have gone on that long because as an audience you want everything to fall back into place again.
"So yeah, it is good to hurry it along a little bit. We had to hurry it along because of the complaints and stuff, but yeah, I get the baby back in late April."
Discussing the complaints, she added: "I think there were around 13,000 - out of 13 million viewers, it's not that bad."
Scenes showing Kat reunited with Tommy were filmed earlier this month.
> EastEnders baby swap ending revealed?
> Click here to read our EastEnders spoilers