A poster of the solar system is always good. A long one with good detailed renderings of the planets, maybe with facts next to them. She can get into the facts at her own pace. There are almost too many to choose from when "posters of the solar system" is googled. Here's one, although there may easily be others with more visual impact.

You can't go wrong with the classic full photo of Earth taken by Apollo 17, or "Earthrise over the Moon" by Apollo 8. A less frequently seen one includes the Apollo 11 lunar module as it ascends from the 1st Moon landing. That odd looking spacecraft could spark questions over the years that'll lead to many long answers.

For rockets and spacecraft I suggest the forward looking ones that will be around while she's growing up. The newest current one is the Dragon capsule on top of the Falcon 9 rocket. It will be flying crews for the coming years. Photos of it are not rare. The forward looking one is the SpaceX Starship, it's trying to leap two generations of design and technology. It also looks awesome. The SpaceX official Flickr site has some crazy good recent photos. Afaik the file size is good enough to print, if you know someone/some store with a largish format photo printer. Yes, those are real photos, not CGI. If you're not familiar with Starship: it's the tallest and most powerful rocket ever, it's fully reusable (both parts come back to land), and the first flight will be by March.

An iconic picture or two from the Apollo era will be nice but she should be looking forward. The Artemis program will be unfolding into her teen years but I'd downplay the SLS rocket and Orion capsule. They won't be flying for long if Starship is successful. They're here for the present but in design and concept they're old tech, backward looking tech.

My favorite source is Tony Bela, an awesome old-school illustrator who is very up to date. His site has plenty of infographic posters, not too large. I used to love the infographic illustrations in magazines when I was a kid during the Space Race, at 9 or 10 years old and onward. I'd pore over them over and over. Maybe good for her now, or maybe better for later.

If you're not into rockets you can still leave one Easter egg for later. She'll think it's just a cool imaginative picture - and be very surprised to learn at some point it's for real and launched in 2018. Actual astronaut not included, lol.