half-sister

Sándor György Gergely Lóczy
Private

Both of those profiles do not have a mother connected to them, but their father does have a wife. Is this the spot where you are having a problem?

Of course they have a mother, it's Katalin Loczy Marzso de Verebely, wife of Dr. Lajos Loczy de Locz - I am trying to correct the wrong entries!
Here it is: Sandor Loczy, Louis de Loczy and Magda Elteto (née Loczy) are all siblings, their biological father is Dr. Lajos Loczy de Locz.
However, the father of Dr. Lajos Loczy de Locz is also named Sandor Loczy de Locz and his wife is Maria Kun.
Sandor Loczy (who dropped the "de" from his name, was my father, Louis de Loczy was my uncle, Magda was my aunt, Dr. Lajos and his wife Katalin Marzso were my grandparents. my mother, Sandor Loczy's wife, is Eva Loczy (née Kovats de Poltar) whose maiden name was changed to Kovacs. She had 4 siblings, whose names I have yet to enter (I found a few of their families on another tree, that of my maternal uncle's son).
Louis de Loczy's wife was also Magda (née Gomperz) whom I have not yet entered, as well as their son, my cousin Louis Loczy, who is still alive.
I know it's a little confusing, due to similar names, so please tell me how to proceed for the corrections.

There are a couple ways to fix this.

The easiest is to start from the tree, or the profile page, and click on edit. From the edit window, select the Relationships tab. Once on the Relationships tab, you should have a drop down box for the Parents. Both Dr. Lajos alone and Dr. Lajos & Katalin should be options in the list.

You'll need to do this for both Sandor and Louis. Once the correct parents are selected there will be no more mentions of half-siblings.