Kitties use their body language as well as vocalization to pass various messages to human beings (their owners), other pets and cats. While trying to interpret what your fluffy friend is trying to tell you, you should consider the context, other body languages as well as vocalization.
For instance, your cat may stare at you when it wants food, needs attention, is scared, is curious, wants to be entertained especially when bored among other reasons.
On the other hand, kitty may meow at you when she is ill, stressed, wants food, lonely, wants attention, wants to be let into the house if she was out, saying hi, contented, growing older, or she is on heat, among other reasons.
From these, it is sensible to conclude that if a cat stares at you and meows, the most probable reasons would include being hungry, seeking for attention, he or she is stressed or wants to be entertained or play with you.
However, also consider the pitch, length, frequency, and volume of the meows. For example, a short one may be a greeting while multiple ones may indicate excitement to see you. Furthermore, kitties make low pitched meows when complaining, high pitched when angry, or mid-pitch when pleading for something such as food.
Finally, do not forget to consider other body languages and consider the context when it happens. For instance, if this occurs when her mealtime is near, then it is food that she wants.