In a word, absolutely. As long as the couple is open to life, it will be up to God whether or not He will bless them in that regard. Never underestimate… remember Sahra (Abraham’s wife) was 90 when she conceived! God bless.
My understanding is that yes, sterile/infertile people can marry, because they are physically able to consummate their marriage. People for whom intercourse is impossible (for instance, people with ambiguous genitalia) are called to be single.
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