Maxi-Cosi - Romi

Bring the seat. It’s worth the effort. Board early and get it set up. Make sure it’s FAA approved, there should be a sticker on it. We purchased a super light one for traveling and it’s been a lifesaver for long flights.

We bought this one off Amazon, it looks like it’s out of stock right now on there. https://maxicosi.com/products/romi-2-in-1-convertible-car-seat-cc228

Lots of recs below for the Cosco Scenera. If you care about this sort of thing, the Maxi Cosi Romi is the exact same carseat but with "clean" fabric (no fire retardants, PFAS, etc.) and more padding. If your 4 year old is 40lbs and 38" tall, you could do a booster seat instead. You can also rent from BabyQuip at your destination if in the US - the person will bring the seats to you at the airport.

Maxi Cosi Romi is a PFAS free travel car seat. We love ours, it’s so lightweight and simple design (so I don’t worry it will get damaged checking it). Nuna TRVL would be a stroller to consider. 

I don’t know if you’ve noticed but the G-luxe doesn’t have the handle bar - it has two split handles. I decided not to get it because of that. I got the Maxi Cosi Romi travel car seat, it’s flame retardant free.

Will both babies be lap infants? There can only be one lap infant per row so just keep that in mind! The Cosco Scenera Next is an amazing travel car seat - definitely my top choice as it’ll fit your 4mos well and will last most kids to about age 3, all for $60. Or the Maxi Cosi Romi is an “upgraded” Scenera next that is identical but offers premium lower anchors for an easier install- that may be worth the upgrade price or not, but it’s otherwise the same and also great for travel! Stroller wise, how much are you wanting to spend? If in budget I’d look at a Valco Slim Twin, Nuna Trvl Double or Silver Cross Jet Double- they’re all pretty fancy but they’re all much lighter and smaller than the donkey, and they all fold in one piece. They all also recline enough that I’d be okay letting 4 month olds sit in the stroller seats. I wouldn’t want to check a multiple-piece or huge stroller either, but I have gate checked my Valco Snap Duo Trend dozens of times without any issue whatsoever. There are also cheaper umbrella style double strollers but I would be hesitant to use them at 4 months because they don’t have the same deep level of recline and most of them probably list 6 months and/or sitting independently as the minimum requirements for kids to ride in them.

I would def bring a car seat for both safety reasons and to keep her restrained if she’s insisting on moving around. We have the Maxi Cosi Romi which is FAA compliant and my son actually prefers it to his bulkier one. Paperback picture books, sticker books (better than coloring imo), and lots of exciting snacks will get you through.