Maia, she only just turned two, give her time to develop, it doesn`t sound unusual for a two-year-old. She is just entering the "terrific-terrible" twos, exploring her independence and abilities. Quite likely she will tend to act out more if her speech had been delayed before. Sure you can help her to use her words instead of acting out and yes, don`t pay too much attention to her during those moments so as not to instill bad habits. But aside from that, it may just be her temperament. Some infants/toddlers/preschoolers need more space, less people, less stimulation than others in order to function properly. It`s not a coincidence that they recommend for birthday parties: One visitor per year of age - or else she will be overwhelmed. My son was just the same way, I still remember his third birthday in horror, but once he turned five he was really socially matured.
It is always a good thing to seek advice when you feel overwhelmed ,she was probably trying to have everyone pay her attention as it was her birthday,Maybe you over react to the situations and she acts out more. Is it possible she was showing off and you thought it was over the Top, and then it escalated due to your intervention, would it have caused you a problem to allow her to be herself Whining and all, back off a bit and see if it helps.