Hi Searest,
To aid the axolotl in healing, I would move the her to the fridge. Fridging will help calm the axolotl by providing a stress free environment in which she will thrive (axolotls love the cold). The fridge also slows the axolotl's metabolism, which should help slow the bleeding.
A guide to fridging:
http://www.caudata.org/axolotl-sanctuary/Fridging.shtml
It's imperative that the water be kept cool and clean. Issues with the water quality can quickly lead to infections.
Keep a close eye on the wound for possible fungal infections.
While the axolotl is enjoying her holiday in the fridge. Could you please give us a rundown of the tank setup?
How long have you had the axolotl?
How large is the tank?
Does the axolotl have any tankmates? Tank mates can cause injury.
What are the water parameters for Ammonia, Nitrite, Nitrate and pH?
What is the tank temperature?
Water quality issues, warm water temperatures, and stress are the usual culprits of fungal infections developing on axolotls.
Axolotls have very sensitive skin. Is there anything in the tank with jagged edges which could have contributed to the axolotl's injury?
If you could post a photo of the tank setup and of the axolotl, that would be most helpful.
Welcome to the site!