Anyone know what to do with these cats?

Apologies if I am posting to the wrong place and/or about a forbidden topic but I feel like all other avenues have been exhausted so here we are.

My sister unfortunately neglected to spay/neuter the 3 original cats they were gifted (no funds and no transportation so I am told) and now they have a dozen total cats they cannot afford to feed. They are trying to find a place for these cats (they live in Hillsboro).

They tried reaching out to animal control and the county shelter but we're denied due to lack of space at both locations.

Does anyone know of any places that can take them? Or any alternatives other than a shelter?

Any suggestions would be much appreciated please. My son had severe allergies therefore we cannot take any of them in and I have searched but have been unable to find anything that would work to help them out. I have been paying for their cat food for many months now but this is not a permanent nor sustainable solution.

Thank you and I hope you are staying dry out there.