4 Gan her admire, and her sad sorrows rue,

Gan > did

5 Blaming Fortune, which such troubles threw,

threw > prepared, threw [in Una's way]

6 And joyed to make proof of its cruelty

joyed > rejoiced, took pleasure

7 On gentle dame, so hurtless, and so true:

gentle > gentle; noble hurtless > harmless

8 Thenceforth he kept her goodly company,

kept her goodly company > [courteously kept her company; or: remained in her courteous company]