Any comprehensive overview of history will show that working is part of the normal human condition. Work can be a dreary hopeless grind, which is a consequence of the fall and no part of God's plan for us. Or work can be a challenging and rewarding experience that adds value to your day, because we are using God-given talents, a sure sign that we are doing God's will for us.
That same study of history, or of economics for that matter, will show you that the normal human condition is laid out in community, with different people undertaking different tasks so that the whole community's needs are met. And those tasks are rewarded in different ways, wages and salaries being only one kind of reward and not necessarily the best. Money is a good symbol of value received, but it is not value per se. If we start categorizing people's work as unselfish based on whose name is on the deposit slip, or selfish based on whose name is on the withdrawal slip, we're misapplying the symbol. Within the community, someone -- a wife, a husband, a grandparent, a hand-maid, a daycare -- needs to be caring for the children at any given time. And someone needs to plant the fields, and dig the wells, and maintain the Internet infrastructure. And no one person can do all of it, so we rely on one another.
That woman in Proverbs 31 who was trading in flax in the marketplace and spinning it, planting vineyards with the fuit of her hands, managing a household staff, and weaving tapestries of purple -- she was working! And she had help with her children, or what were all those handmaids doing after she gaveth them their portion? Today we have daycare as an alternative to handmaids (and we have live-in grandparents, and Filipino nannies, and day-homes, and other choices too). Daycare may be "meant" for single parent families but that does not imply that those are the only families it is meant for. It's for whoever is being called by God or constrained by necessity to do some work that precludes caring for children for the duration of that work. And no-one -- NO-ONE -- can decide who that is except the person who faces that Call or that Necessity.
But whether you are called to be with your own children 24/7, or whether you are called to care for the children of others and receive a wage for doing it, or whether you are relying on someone you have chosen to provide that care for your own children while you work at something else, is not the determiner of whether your children are well-reared or not. People who use childcare alternatives are still rearing their own children. The caregivers have considerable influence, but it doesn't begin to outweigh the parents' if the parents care to use their influence. And stay-at-home parents every bit as much as wage-earning parents, if they shirk the role of primary influencer, may find in retrospect that their children were reared by the television and their peer-group.
If you commit to do right by your children by whatever you choose, then your choices are not selfish.