Reminiscing about her summer holiday as the UK begins its second lockdown, the former TOWIE star took to Instagram to share a photo of herself swimming in the ocean dressed in a black bikini and straw hat.
She captioned the snap: "One of my favourite days of this year, out at sea with the family .... no worries, happy & stress free #specialmemories."
Kate's stunning holiday photo did not get the expected reaction, with fans commenting on the use of her word 'family.'
WATCH: Kate and Rio Ferdinand announce pregnancy - and his kids have the sweetest reaction
It began with one fan writing: "Rebecca's family. I’m all for stepmoms etc. And you’ve stepped into a massive hole. But those kids are Rebecca's. And they’ll not thank you for saying otherwise xx apart from that you are a lovely lovely girl. But, those wedding letters to 'your' kids were terrible. Imagine if you were her looking down, or her mum and dad... not cool. Xx"
Rio lost his wife Rebecca in 2015 following a short battle with cancer. Kate – who is expecting her first child with the sports star – responded: "Wow. Very very narrow-minded. Rebecca is their mum & forever will be. A mother can never be replaced. But let me clarify WE ARE family, families aren't just about blood, but who is there for us and loves us unconditionally.
Kate shared a photo from her recent family holiday
"Please think before you speak, are all foster & adopted children family less?! Of course not. Family is about love and choosing to be there for one another. We are family by CHOICE. It's so sad you don't understand, let's hope you never have to go through such heartache to get it."
Kate and Rio are expecting their first child together
Many more followers rushed to show their support for Kate, with one writing: "You shouldn’t have to explain this, but you have done it perfectly. Well said." A second added: "You are an amazing Mummy and will continue to go from strength to strength with your new addition. How exciting for you all, much love."
Another fan commented: "Families are not just blood. Kate Ferdinand you are amazing stay safe, stay happy & take no notice of the negative comments."