Is she sinful for not seeking to conceive with her drug-addicted husband, knowing that she does not use contraceptives and that addiction is a barrier between them?

We do not understand what you mean by "no effort to conceive," because conception is in God's hands. As long as you do not abstain from his bed and do not use contraceptives, the matter depends on God's decree. You do not sin merely by disliking conceiving from him, as long as it remains within the realm of wishes and self-talk. We advise you to counsel your husband and remind him of God and the unlawfulness of what he consumes. If he does not respond, then it is better for you to leave him.