All good.
According to the name search website, the meanings of Tianxin and Tianxin are:
Sweet, the original meaning of the word Tian refers to the sweet taste of food. Heart, the original meaning of heart refers to the heart of a person or animal, and by extension refers to the mind, mind, interior, center, etc. The name "Sweetheart" implies vision, good expressiveness, and artistry. It also implies a person who is resourceful and good at dealing with complex situations. The road to success is smooth and financial resources are rolling in.
Sweet: The sweet taste of food. It refers to the taste like sugar or honey, which makes people feel comfortable, beautiful, happy and joyful. The meaning of the name Tian: Tian means sweet, beautiful, happy and happy. Xin: refers to the fragrance that spreads far away, fragrant. The meaning of the name Xin: Xin means beauty, elegance, high moral character, and a far-reaching statement. The name Tianxin means intelligence, confidence, health, elegance, charm and independence. Therefore, the names Tianxin and Tianxin both have good meanings. Choose according to your own preferences. It is taboo to use uncommon words in the name.