My 2y old says about 50 words but doesn't string words together. she's also very shy and doesn't talk much around other adults. should i be worried ?

Normal: Do you mean 2yrs 1 month, or 2yrs 11 months. It makes a difference developmentally. A female child approaching three will usually string simple words together. But, it's unusual for a young 2 to do so. Please remember that all tots develop at their own pace. Check with pediatrician that she is reaching developmental milestones. Don't dsplay worry. Instead, engage in reading and word games. Relax.