The couple, who got engaged weeks after meeting, are scouring the holiday islands for a suitable place to seal their whirlwind romance.
A friend of the model and Sun columnist said: “Katie hates waiting for anything. The way she sees it she has accepted Kieran’s proposal so they may as well tie the knot immediately.”
Kieran, 25, proposed on Christmas Day and a wedding is expected this month.
It will be Katie’s third marriage.