Did Mary have to be sinless to conceive a sinless child? Why or why not.
Have you ever heard of the Ark of the Old Covenant — how it was kept so holy. The High Priest could only enter at a certain time, etc. Anyone who touched it would die. All biblical quotes.
Mary is considered to be the Ark of the New Covenenat. Christ was the New Covenant and was within her womb, a very holy, Ark.
No. I believe this was addressed in the proclamation of the dogma, but obviously if Mary had to be sinless than St. Anne had to be sinless and right on back to Adam--destroying the whole concept of Original Sin.
It was certainly fitting that Mary be sinless, but it was not strictly necessary.