Answer
Wa alaikum ussalam wa rahmatullahi wa barakaatuh.
Thank you for sending in your question to our website, sister.
Let’s begin with your first question.
Wiping Head Over the Head-Covering
In a nutshell, there are 3 scholarly opinions about this matter.
The first opinion is that this is impermissible in all circumstances. This is the view of the majority of Islamic scholars, regardless of the situation the woman is in.
The second opinion is that it is permissible for a woman to wipe over her headscarf (i.e. her hijab) during ablution, under all circumstances, even if it is easy for her to take it off for doing ablution.
This is the view of the Hanbali school of jurisprudence.
The third opinion is that it is only permissible for a Muslim woman to wipe over her headscarf during ablution if it is going to pose a great difficulty for her to take it off.
For example, this would apply if she is performing ablution in a place where she has no privacy i.e. non–mahram men can see her, or outdoors, where it is very cold and the cold can harm her head.
This is the view of Ibn Taimiyah.
In all the circumstances rendering it permissible to wipe over her headscarf, she may only wipe over it during ablution on the condition that she must have been in a state of ablution when she first put on that headscarf.
Also, the headscarf should be such that it should allow her whole face, including the peripheries of the chin, cheeks, & forehead, to get wet during ablution, while she has it on.
Dress During Prayer
As for your second question about a woman’s clothing for prayer, the basic principle is that it should be opaque and loose, and should cover her completely, with the exception of her face and hands.
Prophet Muhammad (peace be upon him) said:
Allah does not accept the prayer of a woman who menstruates (i.e., an adult woman) unless her head is covered. [Abu Dawud, 641; Al-Tirmidhi, 377; Ibn Majah, 655; classed as sahih by Al-Albani]
When the Prophet’s wife Umm Salamah (may Allah be pleased with her) was asked about what clothes a woman should pray in, she said:
She should pray in a khimar (head cover) and a long chemise (dress) that covers the tops of her feet. [Abu Dawud, 639]
Therefore, it is the preferred opinion of Islamic scholars that even a woman’s feet should be covered during prayer, based on the above hadith of Umm Salamah.
Hence, for her to pray salah in clothing that has short sleeves, would be incorrect, and will render her prayer invalid. The sleeves should cover her arms up to the wrists.
Praying When No Men Are Around
When a woman is praying her salah in a place where there are no non-mahram men, such as indoors, or in a corner of her home, she does not have to put on a loose outer garment (jilbab) over her regular clothing to pray.
Her prayer is valid as long as the regular clothing that she is wearing whilst praying is loose, opaque, and covers her whole body (except her face and hands).
Wearing tight pants and short tops during prayer that cover all of the skin except the face and hands, but cling so close to a woman’s body that they clearly outline its shape, will not render her prayer invalid per se.
However, praying in such immodest garments will classify as a sin, and greatly reduce the rewards for the prayer.
This is because most scholars opine that pants clearly outline the shape of a woman’s entire lower body when she is sitting down, which violates one of the requirements of her prayer.
And Allah knows best. I hope that this answers your questions.
Salam. Please stay in touch.
https://aboutislam.net/counseling/ask-the-scholar/acts-of-worship/fast-prayer-accepted-without-wearing-hijab/
https://aboutislam.net/counseling/ask-about-islam/hijab-recommended-or-mandatory/
https://aboutislam.net/counseling/ask-about-islam/hijab-all-or-nothing/
https://aboutislam.net/counseling/ask-about-islam/wear-hijab-good-muslim/
https://aboutislam.net/counseling/ask-the-scholar/women-issues/the-why-of-hijab/