I’m sorry to hear about your friend’s daughter’s loss. The “substantial services” 45 hours rule for self-employment is per month, not per week. This rule applies in survivors and retirement claims, and only for self-employed persons. So although the SS worker was wrong, it won't seem to help your daughter, unless you meant "month" rather than "week."
If you need the citation to the POMS (SSA’s operating rules) it is RS 02505.65- “Meaning of Substantial Services in Self-Employment.
The substantial services rules for disability cases are much more complex, because they serve a different purpose, i.e. determing if someone is disabled.
