The US is a terrible place to be a poor woman: exceptional among nations belonging to the Organisation for Economic Co-operation and Development in having zero national entitlement to maternity pay, it has no universal healthcare, the highest rates of maternal mortality of any wealthy nation and barely any support with the costs of childcare.
Which way does the migration flow go? Do people walk from Texas to Guatemala for a better life? Float on inner tubes to Cuba? Flee Manhattan for Mogadishu?
No, they don’t? Then the assertion is full of shit, isn’t it?