Why it say his Speed is 15 ft.? Should it be 25?

She's suffering an affliction from the story she's in...

Reduced because of "Frigid Woe" the disease that the plot is formed around. 

If anyone is interested in using this part of the plot from the "Frozen Sick" adventure to springboard a campaign in Wildmount I'll provide my plot hook below. May contain spoilers!

I personally found the "Train giant frogs to be guards" a bit of a weak and disappointing plot hook so I wanted to spice it up by using it to sow a seed as part of a greater scheme.

It's established in the Explorer's Guide to Wildmount that Jagoda Uttolot, is an expert hunter who uses his skills to track and capture rare creatures for his family to sell. I've taken the prompt that from this experience with dangerous wild animals out of the Savalirwood, Hulil & her apprentice Raegrin who are part of the Uttolot criminal family from Shadycreek run (and are also cultists of Tiamat) have, bolstered by their successes in training the giant ice frogs. Come into the possession of some white dragon scales that belonged to Gelidon, the Ancient White Dragon that is resident of Mythburrow. They are attempting to use the dragon scales to grow and birth a White Guard Drake (See VGM pg158). The knowledge of the creation of this Drake was granted to them by Tiamat and they wish to use it to gain favour of Gelidon.

Lots you can do with this as a plot line even at low levels. To seed the quest for the party to finish after the Frigid Woe arc:

• Perhaps they find a note of communication to a separate cultist sect that is performing the ritual (or has already performed the ritual).
• Or they find out through questioning Hulil about why they were training giant frogs.
• Maybe after the group return from Eiselcross, they hear reports of increased kobold raids on the caravans between Uthodurn and Palebank with sightings of a "White Drake" leading the attempts. The cultists, acting as part of the Uttolot family having successfully performed the ritual and used it to gain control of some mountain Kobolds who revere the drake.
  
  

If you wish to establish this plot as part of a dynamic world and want consequences if the party don't deal with the threat at this level you can tie it into a few of the following:

• Uttolot's are granted some favour from Tiamat for completing this task and the cult spreads to more members in Shadycreek Run as they seek to grow their powerbase.
• The Uttolot Family are attempting to move the drake to Mythburrow secretly through a series of tunnels and complexes. Picking up more kobolds along the way to present to Gelidon.
• The Drake is brought to Gelidon alongside any Kobolds, there is conflict with the already existing Yetis that live in Mythburrow.

Love it! I too found it rather shallow. Great idea!

She contracted Frozrn Sickness.

This might help out a lot with my campaign and with characters backstories.