Will the Roman Catholic Church Enforce a Sunday Law?

Yes.

Daniels writes that a “little horn” will speak great words against God, will wear out the saints of God, and think to change “times and laws”:

Daniel 7:25 King James Version (KJV)
25 And he shall speak great words against the most High, and shall wear out the saints of the most High, and think to change times and laws: and they shall be given into his hand until a time and times and the dividing of time.

The “little horn” uprooted three horns, and had eyes like the “eyes of a man” and a mouth speaking “great things”:

Daniel 7:8 King James Version (KJV)
8 I considered the horns, and, behold, there came up among them another little horn, before whom there were three of the first horns plucked up by the roots: and, behold, in this horn were eyes like the eyes of man, and a mouth speaking great things.

There were ten horns which represents “ten kings” that came out of the fourth beast, after which the eleventh “little horn” uprooted three horns or “three kings” or kingdoms:

Daniel 7:24 King James Version (KJV)
24 And the ten horns out of this kingdom are ten kings that shall arise: and another shall rise after them; and he shall be diverse from the first, and he shall subdue three kings.

The fourth beast according to Bible Prophecy is identified as Rome:

So there were ten kingdoms that came out of Rome when it was divided: