How to deal with my mom's new lover of only one month?

I have nothing against him. He and my mom met online about a month ago and met in person a couple weeks ago and they say they are "completely" in love. And they are already talking about marriage in like september and moving intogether and all of this stuff. I feel like they are moving WAY to fast but my mom claims that they "Just know its love" because they are adults..idk but IDK what to do i told her i feel like they are just infatuated with each other and that they are crazy to be talking about marriage and moving intogether and all this stuff so soon. What do u think? what do i do?