The 'Ordinary People' hitmaker - who has seven-month-old daughter Luna with Chrissy - attended the American Music Awards at the Microsoft Theater in Los Angeles on Sunday evening (20.11.16) and was surprised when asked about Chrissy's offer for her best friend.
The 37-year-old singer told 'E! Live From The Red Carpet': ''Umm, we haven't discussed this. We'll talk about it later.''
The 30-year-old model recently said she would have no problem carrying a baby for the 'Keeping Up With the Kardashians' star if she wanted her to.
She said: ''I would be her surrogate in a second. I really enjoyed the pregnancy process - I loved it. Yes. In a heartbeat.
''I did IVF - science is miraculous these days, anything is possible. I hope whatever she does is gonna work out for the best, and it's gonna be beautiful either way.''
Her comments came after the 36-year-old star was warned she could ''bleed to death'' if she fell pregnant again.
The mother-of-two - who already has three-year-old daughter North and 11-month-old son Saint with her husband Kanye West - said previously: ''Lately I've been thinking I would love to maybe have another baby. But like I had two really difficult pregnancies and really difficult deliveries so getting pregnant again it's something that does concern me.''
But her doctor warned her: ''Here's what I think, your pregnancies, you had toxaemia, you had a retained placenta, very traumatic, we're always worried about the next serious complication. I think the potential fear of the whole situation is legitimate.
''You never know that you might not have the same type of problem that might be more serious this time. You're always taking a little bit of a chance. There are situations where retained placenta could be life and death.''
Whilst Kim's mother Kris Jenner bluntly added: ''You could bleed to death.''
Kim has been open about her pregnancy struggles in the past, previously admitting she suffers from placenta acreeta.
Speaking before she gave birth to Saint, she said: ''With the issues I had last time, my risk of having preclampsia and placenta acreeta are increased and there's not a whole lot I can do to prevent it, so my anxiety is a little high leading up to my delivery.''