hi there! Mine is 12 wks old and we continue to battle this as my two older ones are also 6 & 4. Although we don't homeschool we do have to get out for pickups from kindergarten and pschool which messes us up with consistent naps. And evenings are very difficult. I have had success but when they start out with a short nap, it does seem to make the day spiral down.
Now my success has been with sneaking in before the startle with my hand on her bottom. Also, one day I could not get in there in time and she cried then settled about 3 times. then no more. After that I had about a week of no 45 minute naps!! I thought we were cured, but regressed with days when we have to be away from home and she gets too OT. I am still tweaking our A time, the advice I've received has been to extend by 10-15 minutes which worked amazingly the first day I did it.
She never looks tired or yawns until she's in her dark room, swaddled and ready for wind down, then she can seem OT. Our first nap usually goes well, it's the subsequent ones we have to work on.
And if the afternoon goes bad, it takes multiple times for her to stay down at night, sometimes waking until 10 p.m. until she's finally out.
But my point is, you've been teaching the skill, maybe she will mantra cry at 45 and put herself down with the skills you've been teaching her? It's scary not to go in, bc you don't want to risk a full wake up, but it did work for us.
Good luck...I'm also going to find the thread about A times for each age...I think that's what I need to look at.
