Would Tess of the D'Urbervilles have been raped or seduced, according to today's laws in the UK?

I didn't understand your meaning till it was too late (Tess)
That"s what every woman says (Alex Durberville)
How can you dare to use such words! she cried, turning impetuously upon him, her eyes flashing as the latent spirit (of which he was to see more some day) awoke in her. "My God! I could knock you out of the gig! Did it never strike your mind that what every woman says some women may feel?

"Very well," he said, laughing; "I am sorry to wound you. I did wrong--I admit it. He dropped into some little bitterness as he continued: "Only you needn't be so everlastingly flinging it in my face. I am ready to pay to the uttermost farthing. You know you need not work in the fields or the dairies again. You know you may clothe yourself with the best, instead of in the bald plain way you have lately affected, as if you couldn't get a ribbon more than you earn."

"Tess!" said d'Urberville.
There was no answer. The obscurity was now so great that he could see absolutely nothing but a pale nebulousness at his feet, which represented the white muslin figure he had left upon the dead leaves. Everything else was blackness alike. D'Urberville stooped; and heard a gentle regular breathing. He knelt and bent lower, till her breath warmed his face, and in a moment his cheek was in contact with hers. She was sleeping soundly, and upon her eyelashes there lingered tears.

Darkness and silence ruled everywhere around. Above them rose the primeval yews and oaks of The Chase, in which there poised gentle roosting birds in their last nap; and about them stole the hopping rabbits and hares. But, might some say, where was Tess's guardian angel? where was the providence of her simple faith? Perhaps, like that other god of whom the ironical Tishbite spoke, he was talking, or he was pursuing, or he was in a journey, or he was sleeping and not to be awaked.

Why it was that upon this beautiful feminine tissue, sensitive as gossamer, and practically blank as snow as yet, there should have been traced such a coarse pattern as it was doomed to receive

why so often the coarse appropriates the finer thus, the wrong man the woman, the wrong woman the man, many thousand years of analytical philosophy have failed to explain to our sense of order. One may, indeed, admit the possibility of a retribution lurking in the present catastrophe.
Doubtless some of Tess d'Urberville's mailed ancestors rollicking home from a fray had dealt the same measure even more ruthlessly towards peasant girls of their time.
But though to visit the sins of the fathers upon the children may be a morality good enough for divinities, it is scorned by average human nature; and it therefore does not mend the matter.

Here is the text.
Read Chapters 11 and 12.
There may be other references throughout the book but I have not had time to re-read it yet.
www.literaturepage.com/read/tess-of-the-durbervilles-76.html