Hi there! It should work - after you download WishingSarah-GB-ROMS.zip from the download page, you need to unzip it then you'll have 2 roms:
Dreaming Sarah (U).gb is the english version
Dreaming Sarah (PTBR).gb is the portuguese version
Keep in mind that even though there's a language select screen at the beginning, using the US version will not load the PTBR version - you need to use the separate roms.
Let me know if this helps, if it doesn't I'll take a look!
Thanks!