بسم الله الرحمن الرحيم
Ask your daughter to offer two rakah Salatul Hajah in privacy daily after Isha salah and read the following dua 101 times with durood 7-7 times before and after:
يا بديع العجائب بالخير يا بديع .
After that she should supplicate Allah wholeheartedly for a suitable proposal. (Fatawa Mahmoodia 20: 89, 90, Question: 9623, Pub. Idarah Siddiq Dhabel).
In-shaAllah, soon a suitable proposal shall come. Yes, during the menstruation period she should only read the dua and supplicate and must not offer Salatul Hajah as it is not lawful for a woman to offer salah during her menstruation period. You should also pray for her best and suitable match. In-shaAllah, your dua shall be accepted soon. May Allah arrange a suitable and better proposal for your daughter quickly.
Allah knows Best!
Darul Uloom Deoband