The jibe could be seen as a thinly-veiled reference to Coleen's well-documented marriage problems with husband Wayne and reports of infidelity.
Nicola, who appeared on I'm a Celebrity and Celebrity Big Brother, said Coleen should have waited another two months to post her explosive tweet so Rebekah could have given birth in peace.
She told This Morning: "We've got a pregnant woman here that should not be subjected to this level of abuse.
"Coleen should know this isn't acceptable.
"She's said 'it's Rebekah's account'. I don't think she knows it's Rebekah, she's seven months pregnant.
"This could have waited. Coleen said it's been going on for years. Let it wait – be respectful – is this OK to do now?
"She chose to put a pregnant woman under so much stress.
"We don't know who is right or wrong. We have to show compassion. We've got a pregnant woman receiving death threats, and people saying that her unborn baby should die."
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It comes after the expertly crafted post from Coleen Rooney set the internet alight this week as she accused Rebekah Vardy's account of selling stories to the press in the most public of forums.
Vardy instantly hit back, denying the claims and cutting short her break to deal with the crisis.
She later told the Daily Mail she would find who was behind the leaks and said talking with Coleen is like "arguing with a pigeon."
"I said to her 'Coleen, what on earth have you done?'" Rebekah told the paper about her conversation with Rooney.
"It was not an easy phone call. She said to me: 'I'm not pointing the finger' and I said, 'You have just annihilated me in public and hung me out to dry. The whole world hates me!'"
"I thought she was my friend but she completely annihilated me. She said: 'You know, I always really liked you, which makes it harder'."
But Rebekah says the conversation wasn't an argument. "That would be like arguing with a pigeon. You can tell it that you are right and it is wrong, but it's still going to s*** in your hair," she said.