Of course when any Ziyarat or Dua and even Tasbeeh of Bibi Fatima (s.a) has been introduced to be recited we should do same. But in case of Ziyarat e Ashara if you have not enough time you may recite at least one or ten time rather than 100 but not reciting at all means you have reduced the Ziyarat from your side while traditions says it has those parts too. Also we must recite “ Allahuma Lakal hamdo Hamdash Shakerin….. in Sajdah.
But as for as you’re mothers case inshallah she will get the sawab of this Ziyarat as she has recited because she didn’t know but from now she has to recite complete Ziyarat from the authentic Dua book.