Is it permissible to celebrate the conversion of a Muslim woman to Islam by gathering, welcoming her, and giving her gifts, or is this considered an innovation (bid'ah)?

Congratulating a Muslim who has recently embraced Islam, expressing joy for them, and offering gifts, all of these strengthen brotherhood and love for the sake of Allah, fortify their heart, and dispel their loneliness. This is what their brothers do to make them feel loved and surrounded by people. In the Hadith of Ka'b ibn Malik, may Allah be pleased with him, when Allah accepted his repentance, people rushed to him to congratulate and felicitate him. This is evidence for the desirability of congratulating someone who has received a renewed blessing, such as repentance from disbelief and entering Islam.