I know this one give me a minute to dig around.
Okay here's the one Accidentally Funny by Kanna37 and I do believe it to be MA.
www.dokuga.com/fanfiction/story/3713/1?author=4268
That was the first one I thought of but I do know the one you're asking for I have to do some more digging after I realized it wasn't the right one. I think that one's on the Spark part of the website.
i know the story you're looking for and I have to sift through my faves and alerts to find it. From I remember of it, Inuyasha and Midoriko wind up hooking up and it has a sequel. But correct me if I'm wrong, Sesshomaru's Mother winds up choosing between Touga and this other guy. Kagome has a girl named after his Mother and the Warlord kidnaps her with the intention of mating her when she comes of age.
I know what you're looking for I just have to find it. I'm starting a hardcopy collection of everyone's works and writing up summaries for them. I'll keep digging. It's here somewhere.