Laura Haddock is a young, yet very accomplished TV actress. In the little more than ten years she's been acting she's amassed a ton of TV credits, ultimately landing a role in the Marvel Cinematic Universe. I don't see the character of Meredith Quill coming back all that often in the movies though, but it's still cool. 'Infinity War' has enough characters as it is anyway. We don't need to sacrifice 30 seconds of the Hulk just to see Meredith Quill die again.
Along with being in the Marvel Cinematic Universe, she was also in 'Transformers: The Last Knight.' That's two huge franchises to be a part of. I've heard of actors playing two roles in the Marvel Cinematic Universe (Captain America/Human Torch for example or Killmonger/Human Torch), but two franchises means you're on fire.