I know that you may get a mutiple H1B visa as three years,I don't know about H4 for a Canadian PR holder,usually H4 for a regular Chinese passport holder is two entries & six months,but a lady who just got a H4 visa in Vancouver said her H4 just had
one entry.
If you wife need a mutiple entris visa,I think she may apply a mutiple B1/B2 visa with 10 years peroid in Canada first,then apply a H4 twice entries in China with USCIS I-797 .
one entry.
If you wife need a mutiple entris visa,I think she may apply a mutiple B1/B2 visa with 10 years peroid in Canada first,then apply a H4 twice entries in China with USCIS I-797 .