well > much valiance > valour, bravery

4 As for pure chastity and virtue rare, 5 That all her goodly deeds do well declare.

declare > make clear; declare

6 Well worthy stock, from which the branches sprang 7 That in late years so fair a blossom bore

late > {Recent; belonging to an advanced stage of development [of the line of descent]}

8 As you, O queen, the matter of my song,

queen > [Elizabeth] matter > subject

9 Whose lineage from this lady I derive along.

along > in full; from end to end, in a linear manner; hence: directly

304.4