What is the ruling on the maintenance of children born to a Mukatab and a female slave (ammah) or a contracted slave (mukatabah)?

Primary text

If a Mukatab has a child from a wife who is also a Mukatabah, the child follows them in their contracted status and is suspended upon the mother's fulfillment of the contract. If the mother fulfills the contract and becomes free, the child becomes free; if she remains enslaved, the child remains enslaved. Their maintenance is due from what is in the mother's possession because they are considered in the status of herself, and her maintenance is from what is in her possession. Therefore, their maintenance follows the same rule. The husband, being a Mukatab, is not responsible for their maintenance because they are slaves to the Mukatabah's master.