Do you like gospel? There are literally dozens of great old-timey gospel songs that can be done in bluegrass style without hurtin' 'em too badly. Some examples:

The Hallelujah Side
Will the Circle be Unbroken
Who Will Sing for Me
Give Me the Roses While I Live
Will There Be Any Stars in My Crown
Are you Washed in the Blood of the Lamb

Then there's some country stuff that should adapt well to bluegrass, e.g. Crazy Arms. And I agree about Bill Monroe's songs. My favorite is "Bringing in the Georgia Mail."

You probably aren't going to get soft, sweet romantic sounds with bluegrass. You probably shouldn't even try. Wait. I just changed my mind. How about some of Jean Ritchie's songs, such as "Sweet Sorrow in the Wind", Black Waters, See that Rainbow Shine, and Now is the Cool of the Day? The first one is the only really sweet one but they'd all work. Also Silver Threads & Golden Needles, Gold Watch & Chain, almost any Carter Family song.

Charlie Waller was criticized for playing songs that "Weren't Really Bluegrass." He answered that there had only been three bluegrass songs ever written. I wish I could remember the three titles he named, something like, "I'm Forever Thinking of my Dear Old Mother," "There's a Hound Dog and a Woman Waiting at the End of the Trail," and "My little Old Log Cabin in the Sky." He said all the bluegrass songs ever recorded were permutations on those three, and once in a while a feller wanted something different; and if the Country Gentlemen didn't steal songs that weren't originally bluegrass, they'd pretty soon run out of things to play.

So anything that can be played with a strong rhythm is probably fair game, tho results are unpredictable.

Or, finally, how about starting your own at-home music evenings with some of the people you meet at the bluegrass jams? Make it clear you're offering a space for people to express themselves in other styles. You could do it as a jam, the way Annap does, or as a song/music circle.

Good luck with it all. - Rita F