A nice bunch of flowers, a box of chocolates or treat her to Sunday lunch in a local restaurant.
The groom's parents usually pay for the rehearsal dinner, which is their gift to the couple. Another small gift to the couple can be given. If the mother wishes to give a small gift to her son of some type, this is perfectly acceptable, although she should also give a small gift to her daughter-in-law as well. If the parents did not pay for a rehearsal dinner, then the value of the couple's gift should be a bit higher.
Yes, the mother should give a gift at one or more wedding showers, but after one larger gift for the first shower then the other gifts can be much cheaper such as nice hand towels for the bathroom; drinking glasses, etc.
Since you are the boyfriend of the mother of the bride you should go out shopping with your mate and it's etiquette that the gift come from both of you or, she could help you out choosing something for her daughter.
It is not written in stone that a mother has to give her daughter a personal gift, but some mothers may have a lovely piece of jewelry that they have had or the piece was given to the mother by her mother and she may want to pass it onto her daughter. The mother and father of bride do give a wedding gift either the day of the wedding at home or, leave the wedding gift at the reception.
I am going to give my mother a gift bag for her birthday.
flowers are always great to give to them, or a spa gift gard
candles
No, the mother of the bride does not give the groom or his parents a gift, but just gives a gift to her daughter and new son-in-law.
No, giving both the same gift puts them on the same level. Your wife will feel as if she is only like an asexual "mother" to you not a wife. Gifts should be personal and not come in a bundle.
A gift card to a restaurant
You should simply let her relax!
The best gift any child could give to her or her mother is a homade card and kisses.