Mother of the Groom

The well known on-line auction site is always worth a try? My son had a black and white themed wedding and I couldn't find anything locally - ended up with a lovely dress from that site!
Not sure if they knew but they might now

Maybe check with the bride and her mother to find out the colours first. After that you might see if you could find a nice dress or pantsuit in a complementary colour and make sure it's something you could wear again.

My son getting married in September very quiet do but want look good.,!

Someone who I know buys expensive clothes admired the jacket I wore for DS's wedding, stroked my arm and said 'lovely cashmere'.
I didn't tell her that I had bought it in M&S and it wasn't cashmere (only one I could find in the right colour!).

Dress and matching or toning jacket is always safe. Get a jacket that is perhaps a size smaller than usual and you will achieve a more tailored effect. Have a look at charity shops, but you will need to be lucky. Sainsburys TU clothes are always good value, if you have one locally. Don't be afraid of patterns a floral dress with a plain jacket might look great, especially navy/white as has been suggested.

I have worn silky trousers with a vest / shell top and a floaty shirt / blouse + pashmina for warmth if needed. This of course may not suit a formal wedding, but my sons were fine with it and it suited me much better than the usual 'wedding outfit'. In our village church it would be very acceptable, indeed what most of us would wear.
You may well be fine to try buying online for a 'forgiving' outfit such as this. And I would definitely look around the good charity shops, and some of the cheaper High St. stores. My trousers were one of the posher shades of beige which allowed a colourful top.
I also suggest online trying La Redoute who have a great range, not the cheapest, but not too expensive either. I don't know exactly what 'low' means! And I would look at Oxfam online as well - more difficult with sizes but I think worth a try, these kind of clothes have a lot of 'give'!
If you're not used to buying online, don't be tempted by some of the lovely looking clothes from the Far East - a few people have good stories to tell, but mostly not!
And get opinions from a trusted friend.
I just decided to have a look at Oxfam online for myself, and saw this:
www.oxfam.org.uk/shop/womens-clothing/dresses/decisions-size-14-multi-coloured-full-length-2-piece-dress-hd_101179082
Cost £21.99, and would look lovely with a pashmina (cheaper and more flexible than a jacket)

You beat me to it Fairydoll! My dd got married two years ago and I got the most beautiful dress from Just Last Season for £19. I think it had been reduced from about £90. I teamed it with a pair of lovely shoes from Peacocks that were £12. Have a good Google Rachel

You could try the online company Just Last Season.
They sell Jaques Vert and Eastex at greatly reduced prices.
I have dealt with them for a couple of years and never been disappointed. Returns are free.
They also sell accessories and have some lovely clutch bags.
Thoroughly recommend.
Make sure you go to the Sale page. Sorry, no good with links.

You could turn up looking lovely (and expensive!)

I am a different type (small and lumpy) and find that a classic straight dress, about knee-length, and matching jacket work better than faffing around with blouses tucked into skirts. Stick to basic colours and match it up with a colourful scarf. A string of pearls (fake ones if you don´t own the real thing) makes any outfit look classy. M&S nearly nude tights are great. In general, keeping it simple is better and much harder for people to tell how cheap or expensive it was.

I’d go for a comfortable dress, in a silky fabric, you will know if you can wear sleeveless or not.
For the more formal part you could wear a short bolero style jacket, in a plain colour that picks up the colour of the dress.
Hats are worn less at weddings nowadays, Fascinators are more popular.
Have a browse on EBay, under MOBride or MOGroom sections. There’s plenty of ideas and dresses that others have chosen. I sold my MOG ensemble on EBay for 10% of the original cost. But I was very pleased that someone else was having the pleasure of wearing it on such a special day.

Ask around your friends. Bet they’ve got stuff in the wardrobe they’ve only worn once to a special occasion. Six of us have “the hat” that was quite pricey at the time but has been passed around weddings for about 10 years.

You could borrow one of mine if you lived near!

I wouldn't go for something that is very different to what you usually wear, as that might make you feel uncomfortable. Agree about charity shops and not wearing a hat.
I don't know your usual style, but what about looking at Peacocks or Matalan.

sorry wouldn't go for a hat etc....(typo)

At your height and weight I should think you look very well. On a budget you might decide to have a look at the Charity Shops who stock lovely Mother of the Bride/Groom outfits often worn once only. I would probably stick to something classic feeling as you do a bit self conscious- navy and white are always smart. If you like a bit of colour go for it if you are comfortable. I would go for a hat or fascinator they will add to your worry. Charity shops have a wealth of good bags and shoes again not well worn. Trousers and jackets are now very acceptable as well. The key is be comfortable and don't spend more than you can afford these outfits rarely get worn twice. I hope you have a lovely day.