Per Hinduism, where can married lady wear Sindoor?
What if the lady has bangs, i.e. no obvious part in the hair.
I personally feel one can apply sindoor just anywhere on forehead or head. What matters is the reason and emotion behind it. It is beleived that applying sindoor is related to in long life of the husband.
There is a good story related to Sindoor from the epic Ramayana(source of the story: https://www.scoopwhoop.com/amp/inothernews/lord-hanuman-interesting-facts/)
Once Seeta was applying sindoor in the name of Lord Rama, and Rama's greatest devotee Hanumana saw it and asked the significance.
Seeta told him that applying sindoor increases the life of the Husband.
Being the greatest devotee of Rama , Hanumana thought Lord Rama is not only Seetas beloved one but mine also. Thus he started applying Sindoor all over his body for the maximum longevity of Rama.
So now you must have marked that when Sindoor is applied , the emotion is more important and not just the position!
Having no obvious part in the hair is not a problem. I have seen many women wear Sindur at different places than the part.
Women wear Sindur based on their preferences. I have seen women apply Sindur just at the part, and places other than the part.
If a person wishes to wear Sindur, it is sufficient just to wear it. Not wearing at the part does not do any harm.
Sindoor is traditionally applied at the beginning or completely along the parting-line of a woman’s hair (also called maang in Hindi or "Seemandarekha" in Sanskrit) or as a dot on the forehead.
So, see, if wearing Sindur in Bindi form is also accepted (Sindur for married women only), then there will be no problem in applying it in some place else.
There is no hard and fast rule that you have to wear it in a particular place.
If there is no clear parting on a woman's head, then she can either choose it to wear on the middle of her face i.e. in straight line to her nose or she can wear it where she chooses. But remember, it should not be too far away from the middle of her forehead.
The practice is to wear it on the Seemanta or the parting of the hair.
The Lalita Sahsranama from Brahmanda Purana uses the words "Seemanta Sindhuri" which clearly indicates the exact place where one should wear the Sindhoor.
Shruti seemanta Sindoori kruta paadaabja dhulikaa,
Sakalaagama Sandoha Shukti Samputa Mouktikaa/
The particles of your Lotus feet tuns red as S induri which adorns the foreheads of virtuous women;
From a dictionary you can check the meaning of the word Seemanta which basically here means the "parting of the hair". So, the lady should part the hair and put it there. If parting the hair is not possible for some reasons then I don't know what is ideal for her to do.
Seemandarekha is nothing but the parting-line of a woman’s hair (also called maang in Hindi). Seemandarekha is sanskrit word, means Maang.