First, consider a seat that attaches to the table to bring her closer to the family. Her high chair may make her feel separated from the rest of you—that she's not part of the dining experience. She may also be more independent than you realize and is trying to tell you she wants to feed herself.
Then again, at 9 months she may prefer the ease of taking all her nutrition from the bottle. This is not a good thing, but it happens. You'll have to be strong and not let her take control of the situation or it will continue through her toddler and early childhood years. Put her in her chair as usual but remove her as soon as she starts to make a fuss. Don't offer the bottle at this time. When she learns that she is there to eat, and that you won't give in, she'll start to be more compliant.
Don't let her see your frustration. This can become a game to some children. I promise she won't suffer nutritionally. Remember, you won't see results overnight, but establishing a routine with consequences to behaviors will pay off in the end.
Finally, please don't compare your child to others. While they may advance in certain developmental areas, there are also things she will do sooner, and better, than other kids. Comparisons only make parents feel inadequate.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.