1. Would you travel with a 3 Month Old or would you wait a couple more months to, say, 6 months when naps seem to stabilize and DD needs less daytime sleep?
i woudl and did. and i was told by friends with experience that it was the easiest age of all (i did it by myself from Sydney to NYC so my stress levels were high and i cried from tension, but if you do it with Dh you shoudl be fine). having then traveled with alex at 8 mo and then again from 10 1/2 - 12 mo i do think under 6 mo is best as they are less mobile and more portable (no solids to worry about, etc).
2. How much will this throw off her routine and how long will it take to get back on track? I REALLY don't want to have to go through the 4 nightmare days that it took to get to this point!
this all depends on how many time zones you cross (we had a 14 hour time difference at the time so it took a while and she woke at 4am for feeds for ages - i was there for 3 1/2 weeks) on the 10-12mo trip we had 5 horrendous nights as she was upset and crying (after being an angel at home) as i think it was very disorienting sleeping at grandmas in a porta-cot, etc and she was scared without us - so Dh slept in the same room as her on a twin bed and that helped reassure her - after 5 days she was on-routine
when we traveled at 8 mo only backwards 4-5 hours she did fine.
be prepard for the fact that things migt be in a state of upheaval for a while, but you can still have a great trip and when you get home you will also have possible adjustment (we had 2 weeks of nightwakings whie adjusting to home and new time zone). buit i truly believe that unless you plan to stay home forever you shoudl take advantage of any opportunity for a family holiday and try to take deep breaths.
i will have to take my own advice as we go on our first "family of 4" trip in March to New zealand for 2 weeks with a (then) 1yr old and 2 1/2 year old. i am terrified but the trip is required and i will have to make the most of it.
3. What gear would you recommend we take? We feel like we have to take the entire house!
figure out some small toys that dd likes so you can have variety - better to have 10 small toys that you can rotate/toss in nappy bag than 2 big ones to lug around (i brought her gymini in my suitcase but now think that was unnecessary overkill) at that age the best things i brought to play woth were her favourite hanging bits form the gymini, a couple of rattles and little stuffed toys/teethers to explore, shake, chew, etc MULTI FUNCTIONAL is best.
take stroller (lightweight one that you can take on plane and walk around airports...), assortment of clothes and nappy needs on plane in case of poo/vomit or delays, if you are based in one place you will be able to do laundry so don't pack an awful lot (but baby clothes take up so little room you can fill a small bag and it woudl clothe her for 3 weeks with no laundry :lol: ), a blanket she is used to (this was very helpful - i even laid it in the departure gate area and she had a place to sit and stretch and play), anything of her toiletries that you can't get at destination (any special lotion, bath wash, etc)
anything else can be gotten at destination if required. ask your family to ask around - my mom was able to source a car seat from a friend and later got us a borrowed high chair and stuff, and she bought a baby bath cheaply to have on hand.
don't be too worried as she is so young - you can plan o have 1 nap a day in the stroller if you are in a place where you will do some walking/sightseeing and that gives you flexibility. what i tended to do was get us up and feed Alex and have my breakfast, let her play and then put down for 1st nap, then we woudl head out to visit someone andi woudl put her down for 2nd nap at their house... and then come home for 3rd nap etc We also arranged visits at my mom's house so we could keep dd1 on her routine many days (so llimited disruptions).... the thing about easy it is flexible. just be as consistent as possible and try to have some calm days if you do a lot of visiting so that she has "recovery" days where she has reliable/predictable routine ... for a day or 2 GOOD LUCK