Determine what your goal is. Is this a once in a lifetime trip and you want her to remember it? Then wait - as she will remember nothing. Is this a trip for you to enjoy her marveling at everything and you will be back when she is older? Then 3 is fine.
Agree with above. We all parent and vacation so differently and you know your daughter(s) better than anyone, as well as yourself and your tolerance levels. We took our DD for the first time when she was 3 (I was pregnant with DS). She LOVED it - everything about it, except Small World, she thought the dolls were scary, but loved Matterhorn (I did not ride (as pregnant), she rode with my husband). She adored the characters, especially Pooh, after four visits with him, we said, that's enough. (She is now 19 and to this day has to see Pooh and ride that darn ride at least once a trip
.) The next trip, a couple years later, DS turned 2 (we have the pictures of him wearing his birthday button) and then fairly regularly (pretty close to every other year) since then, along with a variety of other places through the years. Both kids love
Disneyland, my daughter a bit more, I can see her raising her kids on Disneyland like we did.
We chose to parent with the thinking that children join our lives, not the other way around and so we always just did and went where we wanted to go and brought our kids. That being said, did we have dinners that were rushed? Yes. Did we end up getting a meal to go sooner than anticipated? Yes, but our kids have and are awesome travelers (by car and plane) and I believe that is because we took them places while they grew up (prior to everyone having handheld electronic devices for entertainment), without us necessarily trying to instill these things, they learned manners, how to wait patiently, flexiblity, etc. We schlepped whatever gear made our life easier (always a double stroller (not the side by side kind) which made airport travel easier (just gate check it), but the kids were comfy (could nap in the stroller if they wanted to), we had a basket for all the necessities (including a ziploc bag of toys that I didn't care if they made it back home, but gave them something to keep busy with if need be), snacks/drinks, even a compact change of clothes, all the stuff you need for comfort and ease when traveling with littles, the stroller was also great for the walk back to the hotel for mid-day breaks or at the end of the night.
Life in general with kids is being organized, making adjustments for naps, moods, mealtimes, etc., but we simply didn't shy away from taking them anywhere we wanted to go. Every Disney trip has been different based on their ages as their interests and maturity (and height) changed and we have never had a bad trip. Even if they are too young to have a solid memory, looking at Disneyland through your kids eyes is magic in and of itself. We love being able to look back at our photos from the trips and reminisce about the trip, the characters we met that time, etc., and I can't chose a favorite--they all hold something special for me (and my kids.)
Heck, I say bring both kids (you can rider swap) and there are countless people that bring children (including infants) to the parks. Heck the little one is free! Whatever you decide plan your trip (to avoid going the week Star Wars opens for example...), the heat, lines and crowds can all be dealt with by using the many resources for Disneyland planning (especially with toddlers) that exist, keeping your expectations realistic and being patient (with your spouse and kiddos). Stay at a hotel within VERY easy walking distance because that will make a huge difference (our first two trips we stayed at Paradise Pier (not the closest, but at that time, it still had it's own entrance into DCA), and BWPPI...that literally is about the closest you can get. I find if you do those things you will enjoy yourself and your kid(s) will too, regardless of age, and you'll have wonderful memories to look back. I bet you'll be mentally planning your return before you even leave (I still do that.)
