A company that is successful enough to still be a going concern 5-7 years later is generally in good enough shape to either pay off the original investment (not converting the "convertible loan"), or make interest payments, or raise new money to buy out the original investors[].
[] In a case like this, buying out the founder's mother is less of a red-flag than buying out the Angel investor.
[] In a case like this, buying out the founder's mother is less of a red-flag than buying out the Angel investor.