I know, right? But it actually works. Merry and Éowyn have a desperate, tomorrow-we-die tumble in the tent before the Battle of Pelennor Fields. Éowyn meets Faramir in the Houses of Healing and falls in love while Merry goes back to the Shire after all is said and done... but Éowyn realizes she is pregnant. She decides that her daughter would be better raised in the Shire, since Hobbits are more understanding about illegitimate children then Men, so Merry takes her. Merry and Pippin raise her until Merry falls in love with Estella and... yeah.

Do try it, even though your brain imploded! It's actually written VERY well and is perfectly canon-compliant (well, except for a few bits from the appendices that get thrown out).