A friend who has a baby who is about 6 months asked me for a list of things she might want for Christmas. You might want to add these to a registry - or not. Also, good info from an occupational therapist standpoint on infant seats/walkers/exersaucers…
At 6-9 months, she'll be into grasping things, so different textures, and enjoy things with direct feedback. And chewing! Here are some of Soren's faves from that time period (many that he still plays with today).
Soft blocks (we didn't have these exact ones, but something very similar...)
Baby Einstein - Buttons make music! Every kid has this. It is awesome. For us it was a car toy, and easy way to entertain him for at least 10 minutes.
Stacking cups - we have a generic set that also has holes in the bottom, which is great and we still use in the bath, but I always wanted to get these Tobbles stackers.
Things to encourage movement and crawling...so anything hat moves. Add a cause/effect action if you can, like this Inchworm does. (The one we got our first kid required a big button to push and it was too finicky. This seems more fool-proof.) Or toys that wobble are also good. Anything that makes them track and reach.
Plastic keys, plastic rings, rattles on rings, little mirrors, etc. - small, lightweight stuff she can easily hold.
And the same thing but in larger form that you can prop on her lap. Lamaze makes great stuff. We have the robot, but they are all neat.
Toys they can sit up at go over well too - like this little piano. (And this makes for great photo ops!)
The other thing is you might want to ask for things to childproof your house - cabinet latches and things. Because she'll be pulling herself up and maybe crawling in the next 6 months and you don't want whatever it is to crash down on her.
Generally, speaking -
Exersaucers and the like are horrible from an occupational therapist perspective. Babies need to move. It is how their brain works. It is why they like us to carry them - because they are moving. And forcing a baby into a position that they cannot hold on their own (sitting when they don't actually have the stability, standing when they don't have the strength) can trick their brain into them thinking they already have the skill, and can further delay them. 2 quick articles: