Observe her attitude
The most important thing in this regard is to observe the attitude of the 10-year-old girl. It is of utmost importance that you observe her behaviour, and determine whether she is an introvert or an extrovert. Is she fun loving and adventurous, or more of a stay at home child? In this way, you can gauge her interests, and gather information about her favourite books, movies and hobbies.
Observe the financial strength of her parents
Nothing is better than helping people in need. Thus, if the parents of the girl are financially unstable, you can do something that might help her in living her dream, like getting her something she needs which her parents are unable to afford.
Go to a decent toy store
After you have analysed the girl properly, it is strongly suggested that you go to a decent toy store to explore your options. You must take some time out and properly explore the store, so you can obtain an idea about all the recent trends. If you want an opinion, you can also talk to the store in-charge, as he/she might be able to guide you.
Talk to her close ones
In order to gain more clarity, you must talk to her parents, cousins and close ones, to obtain a clearer understanding in regards to her interests. Undoubtedly, they will know more about her than you do, and will be able to act as guides in helping you understand what pleases her the most.
Give something useful
After you have analysed the shop, you must think of gifting her something sensible. You can also give her some money, to spend or save as she chooses. Gifting her the latest book by her favourite author, or any game or software that she might have wanted to purchase, is also a good idea.