help about long-term visa

naming

I want to apply for a long time visa, at least 6month -1 year for my girl friend from china. Any ideas?

I have applied entry visa for her twice via SAVE earlier this year. While everytime she entered Singapore, they gave her 30 Days to stay. I am wondering how to apply for a visa that allow her to stay longer, at least 6 month or 1 year.

Another question. I have applied entry visa for her twice this year, can I apply again for her? is there a limit of application frequency?

I am PR but currently umemployed.

Sorry i was typing english ... I can read chinese, but this computer doesn't have chinese input. Feel free to answer me in chinese... Thanks