你的句子宜用复动词 live：

What friends she has live abroad.

=The (few) friends she has live abroad.

what后面接的是单数名词，则用单词动词。如：

What money he has is yours.

=The (little) money he has is yours.

同意千千老师的解答。下面引用夸克“语法大全”中的一个解释：

【1】what +可数名词复数+主语+谓语动词，作主语谓语动词用复数。what +可数名词复数强调全部。

What books she has are very interesting.

=All the books(that/which) she has are very interesting.

【2】what +不可数名词单数+主语+谓语动词，作主语谓语动词用单数。what +不可数名词单数强调全部。

What milk she drinks is very healthy.

=All the milk (that/which) she drinks is very healthy.

【3】what +few+可数名词复数+主语+谓语动词，作主语谓语动词用复数。what few强调少/仅有。

What few friends I have are kind to me.

=The few friends (that/which) I have are kind to me.

 【4】what +little+不可数名词单数+主语+谓语动词，作主语谓语动词用单数。what little强调少/仅有。

What little time he has was spent with his children.

=The little time (that/which) has was spent with his children.