When you told Arthur that he was going to be the father of your child, he couldn't help but be on cloud nine. It was obvious. He was Arthur, after all.
The 9 months of waiting seemed like an eternity to both of you. You had been preparing for your child for a long time. Arthur had to make a difficult choice between the gang and his future family. And deciding that he wouldn't make the same mistake again - like the one with Elsa and Isaac - he built a small ranch, got some animals, gave you a ring, promising to marry you as soon as the Pinkertons weren't biting his ass.
To say that he wasn't thrilled when his little daughter was born would be a blatant lie. From the moment he first heard her cry, saw her tiny nose, her fair hair that would undoubtedly later take on the color of his hair - you still argue about this from time to time - he swore to you, to himself and to this little bundle of joy in your arms, tired from childbirth, that he would protect her.
And then she said, opened her eyes - your eyes. Then her first word. Surely - it was "daddy". Of course it was. He picked her up every day and played with her, repeating the same "say daddy", then she learned to crawl. And it was all wonderful - him, you, and his little miracle under one roof - what could be better? Oh. It was better. Then, when your daughter finally took her first step!
It was almost funny with the shock and almost panic, Arthur shuddered and automatically stretched out his arms, at the slightest false movement of hers, ready to catch and protect the baby from falling. He glanced at you, noticing the slight giggle on your face, “I’m just worried..” he muttered, watching with slight concern as his daughter happily walked towards him.