Although I do love the Amora (Mira), I can see a slight difference in color when you compare it against your mother's diamond. I think it's the difference in cut that stands out more than the color. You will probably be much happier with an Asha temporarily and a H&A Amora gem in the long run.
+1
I too, saw the difference in the last pic (next to your mom’s, despite the pic quality/blurry).
Right away I noticed that your stone has a greyish color, a slight tinge of green. Now, it might have been obvious to me because I’m probably VERY color sensitive and your mom’s ring is right next to it.
I have an RB in H (1.5 ct), while it looks pretty I much prefer the color f/g cushion that I have.
I believe my Krupps is H too, and I think that color goes perfect with step cuts. Again, all just personal and honest opinion
ETA: I think that you’d be happy with an Asha while you’re waiting for the H&A Amora. Consider ordering the stone first to see IRL. Good luck!