The 10th Swapna that Mata Trishla saw is commonly understood as a lotus lake / lake full of lotuses.

Meaning in English:

It signifies purity, beauty, auspiciousness, and spiritual prosperity. In Jain tradition, it is one of the 14 highly auspicious dreams seen by a Tirthankar’s mother before the birth of a Tirthankar.

If you want, I can also give you the full list of all 14 dreams in English.