Sure man you give it a shot here my save file she has already 100AP i bought everycastle upgrade now already did the required scene that was suppose to unlock those 2 scenes but I still cant get them to trigger im using both the cheat mod and gallery mod to max her out the other characters seem to work fine its only her im having a problem with.
I was looking through your most recent save, and I realized that there is one thing you're missing regarding the horse scenes. You can buy a horse from a stable-master in Slinsk. After that it shows up in front of your castle entrance, and you can use it, from your inventory, as a one way trip back to the castle. After you buy the horse, you can go up to Meredith, flirt, and be reassuring, and get her to have sex with the horse and you to start. This is a different scene than the one you were technically aiming for, but it might kick start your gaming to queuing up the other horse events at the stable.
Another thing, since you're still early on in the game you'll need to do a bunch of side-quests. If you're trying to get a specific event/interaction at the castle, use the abundance of side-quests to your advantage. Roundscape doesn't measure time passing by traveling around. It measures time passing by quests completed. For instance when I loaded up your save Meredith had no scenes available. I did two quests in Ornesse, with your save, time moved forward, and Meredith had a new scene with one of the aliens in her cabin available. Then I got the horse scene after that alien event. So after each quest and side quest you complete, check back around the castle for new scenes. It wont always be a one to one ratio, of quest to event available. However it's the best way to start events that have queued, for an npc, because you meet all the requirements. Also save before you talk to any npc in the castle, or on castle grounds, for events. Sometimes if you say the wrong thing you'll be locked out of the dialogue/scene.
I'll let you try it out, get the horse, complete some quests methodically, and check back in on the castle repeatedly. Rather than risk messing with your switches for now. (Note a lot of times a scene's image will not load if I force it). If for some reason the dog event still doesn't happen, after you progress for awhile, let me know and I can try and edit that.