I would not limit her availability of salt and minerals. Provide both in a loose form (horses often do not lick blocks enough to get what they need). Give her a cup of each in a bucket and let her have at it. She will gobble down a few pounds of each. Don't worry. She's just replacing her stores and she will drop down to a few ounces per day usually within the weeks.
There is no need to provide a separate electrolye. Electrolytes are nothing more than small amounts of minerals, Na, Cl, Ca, P, K and Mg, in an expensive package. A nationally available loose mineral product that is superior to most is Moorman's Grostrong. You want to find one that has high values of Ca (20-30%), P (5-15%) and Vit A (100,000 IU/# or higher). That will limit the amount of salt they can mix in as well.