On shared names between a chosson or kallah and a future in-law, and on adding a name, the Rebbe's guidance:
When the names are not exactly the same, there is no issue. Nor is there a problem when one of the names is used only occasionally, or when each person is called by a distinct name or by their full name (IK 901, 1068, 2485). As an added measure, use all of one's given names when called to the Torah and when signing documents (IK 901).
Where there is a concern, adding a name resolves it, for example when a kallah shares her future mother-in-law's name. This should be done with the guidance of a rav and according to halachah (IK 6104, 9079). The Rebbe sometimes also advised adding a name when a shidduch is delayed or after a broken engagement, together with strengthening Torah and mitzvos, checking tefillin and mezuzos, and giving tzedakah daily (IK 6424, 6638, 9079).
In one letter the Rebbe confirmed that the chosson's name posed no issue according to his father-in-law, the Previous Rebbe (IK 9096).