Hi,
Ah I've managed to track down where the language conflict is coming from.
It seems like your template's language file is defining it at /templates/rt_osmosis/language/en-GB/en-GB.tpl_rt_osmosis.ini line 128.
You can choose to remove it but I am not sure if removing that line affects your template in any way or not.
(I personally think that this is not a good practice by the template to define such general language texts. We usually prefix it with an identifier such as COM_EASYSOCIAL_*)
You might want to consult the template provider on this string to see where they stand on the word Parent being translated to Self.