Stayed at The Nellie for a bit longer than two weeks and the stay was much enjoyed. We kept in contact with Ellen, who is very sweet, thoughtful, and caring.
The Nellie is an adorable vintage trailer and the hosts, Ellen and Ken have utilized boundaries on their property so the back yard is "your space" and works extra great if you ever begin feeling cramped!
My sibling and I enjoyed having the sound of the water fountain in the background and the transition of space: to hang out under during the day by the fountain in the cool shade and then under the umbrella- grilling, eating, and hanging from sunset on. I loved that my pup could run about freely without worry too. We also found it was only a short walk away to a park up the hill and just a little further walk to a few hiking trails. All the amenities you'll need and especially appreciated the gas stove and strong water pressure (gas stoves just cook differently)!
Altadena is so close to an array of other points of interests, including plenty of good spots for eats that being so close to the I-210 becomes such a freer form to travel on in LA. Might add more miles (depending on destination) than you'd get staying close to other main interstates, but makes up in time. Great spot!