That is correct. In the past hobby expenses were only deductible as a misc. itemized deduction, subject to the 2% of AGI threshhold. All such deductions were eliminated with the new tax law.
She may still deduct the "cost of goods sold". For example, if she buys a lamp for $10 and sells it at the flea market for $15, she only reports $5 of income. If she sold a used lamp for $15, from your household, that you bought many years ago for $25, she does report any income. But she cannot deduct the "loss" on the sale.
