Local languages in this part of the world typically fail to distinguish the gender of third person pronouns; so both 'he' and 'she' are dia in Malay, and though they are differentiated in Chinese writing as 他 and 她, these are both pronounced as [ta] on a high-level tone. As a result, even quite proficient speakers of English in the region sometimes continue to confuse 'he' and 'she'.
From a communicative perspective, does this matter? If someone says:
I have one sister and he works as a teacher
they are unlikely to be misunderstood, though a listener from somewhere such as the UK might find it a bit jarring.
However, breakdowns in communication can sometimes occur. I have been listening to some recordings I made in Guangxi Province, and in the 24 interviews, there are 41 expected uses of 'he' and 'she' and 7 unexpected ones, 4 uses of 'he' to refer to a mother or sister and 3 uses of 'she' to refer to a father or brother. None of these is an issue, as the meaning is clear in context. However, there is one additional instance which is problematic. A female speaker said:
I have a roommate. He er he's live in Shangrila.
In response, I said 'okay', hoping the student might elaborate about her roommate. But when this was not forthcoming, I changed the subject, asking about where she would like to travel to if she had the choice.
The problem is this: it is extremely unlikely that her roommate was male, especially in China; but she had used 'he'. So if I was to ask more about her roommate, should I use 'he' or 'she'? Instead I took the safe option and changed the topic.
It seems that confusing the two pronouns can sometimes be a problem.