You can almost always force the Source Linker to do what you want it to do. In this case, first copy the ID number for Petronell's husband, then change the focus person to Petronelle's husband:

Then use the right side Change Person and paste in her husband's ID that you copied:

and attach his record.

then use the arrows that appear when you hover over the correct spot where they are hiding on Petronelle to drag her to the right spot:

and attach her record.

The other option that you might want to use to really fix this, is to go into the image viewer/editor and correct the relationships first. You cannot do this by clicking on View Image in the source linker. You have to click View Record and then on the indexed record click Edit:

Fixing relationships is a bit of a tricky process. Let me know if you need any help with that. After fixing it, wait until the change has synced through the system, which could take seconds to days, then go back to the source linker and things should line up just fine.

Fixing the index is actually the better route because then the hinting routine when it looks at attached sources and relationships to find other hints for the people involved won't get confused by a parent child relationship being attached as a couple relationship.