Question Lightweight Travel Seat for 4.5 year-old

We have an upcoming trip planned and I am looking for lightweight alternative car seats for our kids. We will have a plane ride and then will have about a 2 hour car ride to our destination and then very local travel while at our destination. We have a 1.5 year old DS riding rear-facing in a Britax Marathon at home. I am pretty set on getting him a Cosco Scenera for the trip since it is recommended here often and is also lightweight and affordable. My son is not particularly big for his age so it should last a while. Where I am getting confused is my 4.5 year old DD. At home she is harnessed in a Britax Frontier 90. She is 40' tall, but only about 35 lbs. I am torn between buying a combination seat where she could still be harnessed and a highback booster (particularly the Graco Turbobooster, since is rated for 30 lbs and up). She is a very compliant child, so I have no doubt she could sit properly in the TurboBooster. I am also not worried about her in a carseat on the plane. The other options I have considered are a Evenflo Maestro or SecureKid. I question whether the additional money and weight is necessary given that she meets the criteria for the TurboBooster and that it would only be used for travel. I am open to other suggestions, but I will say that she needs to be in a booster-type seat like the Frontier. There is no way that she is going to go back in a typical carseat, most of her friends are already riding in backless boosters and she views them as for babies (not passing judgment either way, just not willing to start my vacation with a battle!)

I was going to suggest the Evenflo Sureride. It has high slots and is around $80. It is a convertible seat, so it sounds like you don't want that. I, personally, would not put a 4.5yo in a booster. I don't let the comments of other people dictate the safety of children, but I understand how hard that can be.

At 4.5 and having never been in a booster before I would not booster for 2 hour rides x2, you don't know how your DD will sleep in it and that is a possibility still for most 4.5 yr olds and that length trip especially depending on time of day. I would do the maestro or securekid if your set on a combination over convertible. otherwise i agree with Kac on the sureride that would have been my first recommendation

The Maestro is reasonably lightweight, I am guessing it does not weigh much more than a highback Turbobooster. Plus the back won't fall off from carrying like the Turbo. Unlike the Turbo, you can use it on the plane so you won't have to go through the hassle of gate-checking it. And they can be found for about 20-25 bucks more than a Turbo. Can you tell I loved our Maestro? It was our main seat from the time my son was about 3 to when he was on the verge of outgrowing it by height/weight at 5 years 8 months (and he's around 85th percentile for both height and weight, it would likely last your daughter longer). It doesn't have the "feel" of a Britax or other high-end seat, but I think it's a really nice seat for the price.

We love the Maestro for travel! It's a great seat. I wouldn't booster for the first time on a vacation but that's me.

Where do you live? I'd loan mine out.