1),她能回国么?
Yes, with H4 visa status and I-485 pending, she has to apply for H4 visa in China.
2)如果能,回来的时候,要不要去领事馆签证?如果不要签证,就是拿着那张最近延期的时候给的那张签证(一张绿色的纸)跟这个收据就成么?
She needs to make an appointment and apply for H4 visa to come back to US. To be safe, she should take all related materials with her, i.e. visa renewal notice, your H1B approval notice and renew notice, her I-485 notice et al.