Learn Hardcore Chinese: tā huì chàng.

A very important point: in spoken Mandarin, both 她 and 他 are pronounced exactly the same: tā. So if you only hear the sentence, you cannot tell the gender from pronunciation alone. The distinction is mainly visible in writing.

There is also 它 for it, and it is also pronounced tā.

How do I pronounce 她会唱?

It is pronounced:

她 — tā (1st tone)
会 — huì (4th tone)
唱 — chàng (4th tone)

So the full sentence is:

tā huì chàng

A rough English-style guide would be something like:

tā: tah with a high, steady pitch
huì: hway said sharply, falling
chàng: like chahng with a falling tone

What does 会 mean here?

Here, 会 is a modal verb meaning to know how to, to be able to, or can because of learned ability.

So in this sentence, 会唱 means can sing / knows how to sing.

This use often suggests that the ability comes from learning, skill, or acquired knowledge.