When Rashi wrote the mantra she also wrote the letters as well on the inside. When you watch the previous days episode you will see Rashi doing this whilst innocent Gopi studied.Cunning Rashi upon returning from her drive with Jigar, told Gopi that there was a ruler that may belong to Sarika and was left on the dining table. She told Gopi to get it and give it to her rather than she doing this. Whilst Gopi went to get the ruler Rashi had a look at Gopis book. When Gopi returned Rashi said to Gopi give me a piece of paper I want to write something for you. Silly Gopi opened her book and gave it to Rashi who wrote not only the mantra on the outside but the letters inside. So she may deny that it is her handwriting by pretending that it was Gopi's.