Grow to marry someone is never correct in any context Come to marry someone can be used as a question How did you come to marry? Is asking for a explanation of the sequence of events resulting in the marriage. However in this context Laura, happy the man who marries you is most appropriate

Hola Jordi, I agree with Mike and Tanya. First, the expression "Grow to marry" would never be used. You can use the verb "to grow" in other ways when talking about love, marriage or relationship. For example: "Laura and I have grown in our love for each other over the years." "Laura, the more time that I spend with you, the more my love for you grows." "How can we make our love grow stronger?" Here, we mean "crecer", the process of a relationship/love growing deeper, stronger, greater. Second, the expression "to come" indicates the process, the "how" something happened. For example in a movie, you may here the expression "how did it come to this?" or "how did we come to this?" ---situation, this end, this result, etc... In English, it would not be natural to use the expression "come to marry." In your example, the common and natural way would be "Laura, lucky will be the man who marries you!" or "The man who marries you will be blessed! will be lucky! will be happy! etc.... I hope that this helps you with these 2 verbs. Ask if any questions or need for clarification! Best of luck in your language studies amigo :-)

Just say 'who gets to marry you'.. or 'who marries you'! I think a more natural way to say it would be.. 'Laura, whoever gets to marry you will be a lucky man' or 'Laura, whoever marries you will be a lucky man.