The 'Mama Do' hitmaker has revealed that her sibling's boyfriend proposed while they were all on a family skiing holiday over the New Year break, and she is now busy planning the wedding, reported Daily Mail online.
Lott said that the wedding preparations are daunting, but she feels honoured to be involved.
"It was a really good way to go into the new year because everyone was really happy. She got engaged while we were away and we were skiing so it just made it really lovely, everyone was really happy," Lott said.
"I've been made maid of honour I've been told, which is quite a task because I'm not the most organised of people. I've got to organise the hen night and stuff so I'll get a bit of help off people like my mum and stuff. It's going to be so much fun, I can't wait just to have a wedding in the close family. It's going to be fun."
However, Lott insists she will not be following her sister down the aisle any time soon, adding, "I think it's too early yet. I still feel quite young to do that kind of stuff. But definitely at the moment all the focus is on my sister and her wedding.
"They're just starting to get a house together and I can't wait for her to have babies," she said.