In an instance where a Muslim woman works in a company building and the toilets are public to every companies here, although one for women and other for men. She might feel too inconvenient to do wudhu there. She cannot guarantee that no man will enter (a plumber or one by mistake). In this condition, is she allowed to do tayammum?

Also, in another situation she opts to pray sitted in a chair… although she’s capable of praying normally, if is fine to carry on with that.

In response to this, First, it is highly appreciated seeing Muslim women care for their hijab and their decency, this is a good characteristic of a Muslim woman. Chastity is a mark on sound faith, the Prophet (peace be upon him) said, “And chastity is a branch of faith.

We do recommend to maintain this characteristic all the time.

However, being shy or even modest does not drop the obligatory acts. Offering Wudu’ and Prayer has essential conditions and pillars that cannot be neglected. With regard to doing Tayammum instead of wudu’ with water because of fear of somebody may see the Muslimah unveiled, this is not right and is not a valid excuse to refer to Tayammum as the later is only permitted in case of lack of water or existence of harm due to use of water.

In his answer to this topic, Dr. Rajab Abu Mleeh, stated,

“Tayammum has been legislated for certain excuses and cases such as lack of water or fear of using water due to some expected harm such as in case of wounds in body parts washed in Wudu’. Thus, resorting to Tayammum because of the fears that somebody may view you without hijab is not right. According to the explanation, the company’s building has separate bathrooms for men and consequently if a man intentionally looks at you while you are without hijab, he alone is sinful and there is nothing wrong with you as long as you take all precautions for this.

Moreover, during wudu’ a woman will uncover only her hands and legs for a short time and of course her hair but she can wipe over her hair from under the hijab

As for the part of offering Prayer while sitting, a Muslim should know that standing during Prayer is a pillar, i.e. an obligatory act. A praying person should not avoid it except for a valid reason such being unable to stand due to some illness or anything else. Hence, you have to perform your prayer in its due time while standing, unless there is a real danger in consequence of standing. Try to look for solutions that help  you perform prayer at work, and ask for your rights, putting your trust on Allah.