If you are able to donate: World Central Kitchen founded by Chef Jose Andres are feeding thousands of Ukrainian refugees at the borders. https://www.wck.org/

From the UNICEF website:
The conflict in Ukraine poses an immediate and growing threat to the lives and well-being of the country’s 7.5 million children. Humanitarian needs are multiplying by the hour as fighting intensifies. Children have been killed. Children have been wounded. And half a million children have fled Ukraine to neighbouring countries, with the number of refugees continuing to grow. https://www.unicef.org/