TMZ Sports talked to Stewart -- the co-host of OutKick's The Fade with Clay Travis -- about some of her favorite bets heading into the Chiefs vs. 49ers game.

"I think if you like either team you bet them on the money line," Stewart said.

"A 2-point spread, slight implied odds that the Niners are a little bit better on a neutral field than the Chiefs, which I would agree with here. But I don't know how we see these last few seconds playing out. I think for me, the last I want holding a Niners ticket is Patrick Mahomes to have 2 minutes left on the clock. That would make me a little uneasy come Sunday."

Despite that terrifying thought ... here's the bet Kelly made for herself.

"I did lay -$125 with the Niners, so if you like the Niners, I think you bet them on the money line."

If you're interested in over/unders ... Kelly has some advice.

"What I always tell people, before you bet, think about your game script. How do you think the game is gonna play out? I think we're gonna see a higher-scoring first half here. I like the first half over. I know some really good friends of mine that agree with me," Stewart told us.

"I think the second half is gonna be lower scoring. I think we're gonna see Steve Spagnolo's defense step up, we know the Niners defense has been one of the best second half defenses over the last two seasons," KS said ... pointing out that San Fran's D has won a lot of people money of late.