Well, insufferably long, interminable months, but anyway.
But I only worry about this close-ish spacing for about five seconds; Sylvie has gotten quite a bit of attention in her mere seventeen months on the planet. And I think she will get a kick out of another baby.
She's a feisty little bugger. She can take on three brothers at once, and can crack them up just by saying "Sponge Bob" in Sylvie-speak. How we adore this little firecracker - I don't think she'll let anyone upstage her. Oh, and Sylvie? If you could start sleeping through the night before your little sister arrives, that would score you some serious points.