Hello and welcome to HCM.
Thank you for your query.
Please understand the desire for sexual intercourse or to get aroused by ones partner is purely mental and visual.
Let us try to work on both these stimulants.
1. Psychological/mental: Women (especially after delivery) fell less confident about their body, and even more with passing time. Try to make your partner feel attractive and beautiful. Try to make her feel like she still has the same effect on you that she did previously. This can be achieved by giving her compliments, doing things that make her happy (happiness and an elated mood contributes to an increased hormone production), and give her hints (but, never be direct, as it will only sound crude). Help her around the house, ask her to rest while you do so. Take her for a holiday, stress
can be a real deal breaker.
2. Visual: This will be achieved with your body language towards her. Be kind and gentle when ever you deal with her or are around her. But, in my opinion, the most important thing is to make yourself look attractive to her. If you have stopped caring about your appearance, please concentrate on it. May be lose a little weight, or try a new hairstyle. But, make sure you let her find out that you are doing this for her, or you did this for her and so she would like you in your altered avatar.
Instead of a direct approach, try this one. And if done well, I am sure your married life will kick start once again.
I hope I have succeeded in answering your questions, you could write back to me anytime for further clarifications.