This is not my area of expertise, but it may depend on HOW the title is held. Is it held as "joint tenants" or a "tenants in common"?
If I remember correctly (which isn't necessarily the case), if it is held "tenants in common", you both legally own 50% of the property (or whatever other percentage the title says). The sale would be required to be reported 50/50. If the title was transferred 100% to the parent, then the parent MIGHT need to own that half for the required time (I would need to research that).
If the property was held as "Joint Tenants", you each own 100% of the property. If your mother receives (AND KEEPS) the sales proceeds, you may be able to allocate it all to her. If you paid for the property, you might need to file a Gift Tax return for effectively giving her the property. HOWEVER, if your mother receives the money and just gives it back to you, it is a illegal tax-avoidance scheme, and the sale should be reported on your tax return, not your mothers.
