There are many lenses you could get that should take great portraits. See if you can figure out what focal length works best first, which will narrow down the choices a lot. It's more complicated because your primary subject is 17 months old, not 17 years old.
And maybe you have to imagine what will happen in a few years. The typical range of portrait lenses is 50 to 135mm. Outside this range on either side, faces start to look a little weird, and taking the shots becomes harder. You can find the technical reasons why this is true, or just skip them for now.
When you use the 50mm lens, do you feel like you are the right distance away to frame the shot, including or excluding anything you want in the foreground or background? Distance is also helpful for interacting with your subject, or being discreetly far enough away so you don't change their natural behavior. With an 85mm lens, you will have to be further away, at 135mm further still. Indoors, some rooms aren't big enough for 135mm. You might try using your other lenses just to simulate other focal lengths, such as the 80-200mm zoom. You are just seeing what framing looks like and distance from the subject to get that framing.
Try to estimate how much of the shot you'd want in sharp focus. That probably means your daughter and the whole outfit, but not much more than that - maybe something like one foot. Now you might look at an online depth of field calculator. Plug in your camera and the focal length you're thinking about. Change the distance to where you want to be and aperture (f number) until you see what you'd have to shoot at.
With an idea about focal length, shooting distance, possible apertures and a budget, picking a lens is way easier. It looks to me like you don't need the typical portrait lens that opens to f1.4. If you plug in a 90mm macro lens, you could be at 10 feet, shoot at f9.5 and be able to count stitches on the outfit. At 17 months, wrinkles won't be an issue.